21420624413520 has 320 divisors, whose sum is σ = 79070889853440. Its totient is φ = 5316140408832.

The previous prime is 21420624413509. The next prime is 21420624413561. The reversal of 21420624413520 is 2531442602412.

21420624413520 is a `hidden beast` number, since 2 + 1 + 4 + 2 + 0 + 624 + 4 + 1 + 3 + 5 + 20 = 666.

21420624413520 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×21420624413520³ (a number of 41 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 an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3988489 + ... + 7664808.

It is an arithmetic number, because the mean of its divisors is an integer number (247096530792).

Almost surely, 2^{21420624413520} is an apocalyptic number.

21420624413520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21420624413520 is an abundant number, since it is smaller than the sum of its proper divisors (57650265439920).

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

21420624413520 is a wasteful number, since it uses less digits than its factorization.

21420624413520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11653379 (or 11653367 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 36.

The spelling of 21420624413520 in words is "twenty-one trillion, four hundred twenty billion, six hundred twenty-four million, four hundred thirteen thousand, five hundred twenty".