21670499628 has 72 divisors (see below), whose sum is σ = 60168326400. Its totient is φ = 6545775456.

The previous prime is 21670499597. The next prime is 21670499639. The reversal of 21670499628 is 82699407612.

21670499628 is a `hidden beast` number, since 2 + 1 + 6 + 7 + 0 + 4 + 9 + 9 + 628 = 666.

It is a super-2 number, since 2×21670499628² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 673008 + ... + 704471.

It is an arithmetic number, because the mean of its divisors is an integer number (835671200).

Almost surely, 2^21670499628 is an apocalyptic number.

It is an amenable number.

21670499628 is an abundant number, since it is smaller than the sum of its proper divisors (38497826772).

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

21670499628 is a wasteful number, since it uses less digits than its factorization.

21670499628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1377531 (or 1377526 counting only the distinct ones).

The product of its (nonzero) digits is 2612736, while the sum is 54.

The spelling of 21670499628 in words is "twenty-one billion, six hundred seventy million, four hundred ninety-nine thousand, six hundred twenty-eight".