21471647760 has 120 divisors (see below), whose sum is σ = 72195551064. Its totient is φ = 5718896640.

The previous prime is 21471647759. The next prime is 21471647761. The reversal of 21471647760 is 6774617412.

It is an interprime number because it is at equal distance from previous prime (21471647759) and next prime (21471647761).

It can be written as a sum of positive squares in 4 ways, for example, as 20736 + 21471627024 = 144^2 + 146532^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is a super-2 number, since 2×21471647760² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (21471647761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 596680 + ... + 631640.

Almost surely, 2^21471647760 is an apocalyptic number.

21471647760 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21471647760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36097775532).

21471647760 is an abundant number, since it is smaller than the sum of its proper divisors (50723903304).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21471647760 is a wasteful number, since it uses less digits than its factorization.

21471647760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35833 (or 35824 counting only the distinct ones).

The product of its (nonzero) digits is 395136, while the sum is 45.

The spelling of 21471647760 in words is "twenty-one billion, four hundred seventy-one million, six hundred forty-seven thousand, seven hundred sixty".