21415290624 has 756 divisors, whose sum is σ = 80132411856. Its totient is φ = 5589762048.

The previous prime is 21415290577. The next prime is 21415290641. The reversal of 21415290624 is 42609251412.

It is a happy number.

21415290624 is a `hidden beast` number, since 2 + 1 + 4 + 1 + 5 + 29 + 0 + 624 = 666.

It is a tau number, because it is divible by the number of its divisors (756).

It is a super-2 number, since 2×21415290624² (a number of 21 digits) contains 22 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 an unprimeable number.

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 83 ways as a sum of consecutive naturals, for example, 220776144 + ... + 220776240.

Almost surely, 2^21415290624 is an apocalyptic number.

21415290624 is a gapful number since it is divisible by the number (24) 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 21415290624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40066205928).

21415290624 is an abundant number, since it is smaller than the sum of its proper divisors (58717121232).

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

21415290624 is an frugal number, since it uses more digits than its factorization.

21415290624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164 (or 122 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The spelling of 21415290624 in words is "twenty-one billion, four hundred fifteen million, two hundred ninety thousand, six hundred twenty-four".