21381320512036 has 27 divisors (see below), whose sum is σ = 37466591173851. Its totient is φ = 10676598690264.

The previous prime is 21381320511997. The next prime is 21381320512039. The reversal of 21381320512036 is 63021502318312.

It is a happy number.

The square root of 21381320512036 is 4623994.

It is a perfect power (a square), and thus also a powerful number.

It is a super-2 number, since 2×21381320512036² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21381320511986 and 21381320512004.

It is not an unprimeable number, because it can be changed into a prime (21381320512039) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 13714765425 + ... + 13714766983.

Almost surely, 2^{21381320512036} is an apocalyptic number.

21381320512036 is the 4623994-th square number.

It is an amenable number.

21381320512036 is a deficient number, since it is larger than the sum of its proper divisors (16085270661815).

21381320512036 is an frugal number, since it uses more digits than its factorization.

21381320512036 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6088 (or 3044 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 37.

The spelling of 21381320512036 in words is "twenty-one trillion, three hundred eighty-one billion, three hundred twenty million, five hundred twelve thousand, thirty-six".