21465005760 has 672 divisors, whose sum is σ = 85245488640. Its totient is φ = 4906598400.

The previous prime is 21465005759. The next prime is 21465005761. The reversal of 21465005760 is 6750056412.

It is a happy number.

21465005760 is a `hidden beast` number, since 2 + 1 + 46 + 500 + 57 + 60 = 666.

It is an interprime number because it is at equal distance from previous prime (21465005759) and next prime (21465005761).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (21465005761) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 64848795 + ... + 64849125.

Almost surely, 2^21465005760 is an apocalyptic number.

21465005760 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 21465005760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42622744320).

21465005760 is an abundant number, since it is smaller than the sum of its proper divisors (63780482880).

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

21465005760 is a wasteful number, since it uses less digits than its factorization.

21465005760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 477 (or 464 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 36.

The spelling of 21465005760 in words is "twenty-one billion, four hundred sixty-five million, five thousand, seven hundred sixty".