21378510499536 has 80 divisors (see below), whose sum is σ = 61429042843200. Its totient is φ = 7118645035392.

The previous prime is 21378510499517. The next prime is 21378510499607. The reversal of 21378510499536 is 63599401587312.

21378510499536 is a `hidden beast` number, since 2 + 1 + 3 + 7 + 8 + 5 + 1 + 0 + 4 + 99 + 536 = 666.

It is a super-2 number, since 2×21378510499536² (a number of 27 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (63) coincides with the sum of the digits of its distinct prime factors.

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, 25719351 + ... + 26537558.

It is an arithmetic number, because the mean of its divisors is an integer number (767863035540).

It is a 1-persistent number, because it is pandigital, but 2⋅21378510499536 = 42757020999072 is not.

Almost surely, 2^{21378510499536} is an apocalyptic number.

It is an amenable number.

21378510499536 is an abundant number, since it is smaller than the sum of its proper divisors (40050532343664).

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

21378510499536 is a wasteful number, since it uses less digits than its factorization.

21378510499536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52257873 (or 52257861 counting only the distinct ones).

The product of its (nonzero) digits is 48988800, while the sum is 63.

The spelling of 21378510499536 in words is "twenty-one trillion, three hundred seventy-eight billion, five hundred ten million, four hundred ninety-nine thousand, five hundred thirty-six".