21538689954936 has 64 divisors (see below), whose sum is σ = 67133579086080. Its totient is φ = 5594464922880.

The previous prime is 21538689954923. The next prime is 21538689954979. The reversal of 21538689954936 is 63945998683512.

It is a super-3 number, since 3×21538689954936³ (a number of 41 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5827565781 + ... + 5827569476.

It is an arithmetic number, because the mean of its divisors is an integer number (1048962173220).

Almost surely, 2^{21538689954936} is an apocalyptic number.

It is an amenable number.

21538689954936 is an abundant number, since it is smaller than the sum of its proper divisors (45594889131144).

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

21538689954936 is a wasteful number, since it uses less digits than its factorization.

21538689954936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11655135284 (or 11655135280 counting only the distinct ones).

The product of its digits is 3023308800, while the sum is 78.

The spelling of 21538689954936 in words is "twenty-one trillion, five hundred thirty-eight billion, six hundred eighty-nine million, nine hundred fifty-four thousand, nine hundred thirty-six".