21064625428 has 48 divisors (see below), whose sum is σ = 46177141248. Its totient is φ = 8168076000.

The previous prime is 21064625423. The next prime is 21064625431. The reversal of 21064625428 is 82452646012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21064625423) 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 15 ways as a sum of consecutive naturals, for example, 97078 + ... + 227053.

It is an arithmetic number, because the mean of its divisors is an integer number (962023776).

Almost surely, 2^21064625428 is an apocalyptic number.

21064625428 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21064625428 is an abundant number, since it is smaller than the sum of its proper divisors (25112515820).

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

21064625428 is a wasteful number, since it uses less digits than its factorization.

21064625428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 324364 (or 324362 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 40.

The spelling of 21064625428 in words is "twenty-one billion, sixty-four million, six hundred twenty-five thousand, four hundred twenty-eight".