21151147680 has 1008 divisors, whose sum is σ = 86192187480. Its totient is φ = 4891041792.

The previous prime is 21151147519. The next prime is 21151147687. The reversal of 21151147680 is 8674115112.

21151147680 is a `hidden beast` number, since 21 + 1 + 511 + 47 + 6 + 80 = 666.

It can be written as a sum of positive squares in 12 ways, for example, as 611671824 + 20539475856 = 24732^2 + 143316^2 .

It is a super-3 number, since 3×21151147680³ (a number of 32 digits) contains 333 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21151147687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 167 ways as a sum of consecutive naturals, for example, 571652622 + ... + 571652658.

Almost surely, 2^21151147680 is an apocalyptic number.

21151147680 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 21151147680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43096093740).

21151147680 is an abundant number, since it is smaller than the sum of its proper divisors (65041039800).

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

21151147680 is a wasteful number, since it uses less digits than its factorization.

21151147680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125 (or 89 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 36.

The spelling of 21151147680 in words is "twenty-one billion, one hundred fifty-one million, one hundred forty-seven thousand, six hundred eighty".