21064625424 has 200 divisors, whose sum is σ = 64314946080. Its totient is φ = 6637593600.

The previous prime is 21064625423. The next prime is 21064625431. The reversal of 21064625424 is 42452646012.

21064625424 is a `hidden beast` number, since 2 + 1 + 0 + 6 + 4 + 625 + 4 + 24 = 666.

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 (21064625423) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 21693259 + ... + 21694229.

Almost surely, 2^21064625424 is an apocalyptic number.

21064625424 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 21064625424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32157473040).

21064625424 is an abundant number, since it is smaller than the sum of its proper divisors (43250320656).

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

21064625424 is a wasteful number, since it uses less digits than its factorization.

21064625424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1891 (or 1876 counting only the distinct ones).

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

The spelling of 21064625424 in words is "twenty-one billion, sixty-four million, six hundred twenty-five thousand, four hundred twenty-four".