21304078785 has 128 divisors (see below), whose sum is σ = 45650718720. Its totient is φ = 9298713600.

The previous prime is 21304078759. The next prime is 21304078793. The reversal of 21304078785 is 58787040312.

It is not a de Polignac number, because 21304078785 - 2¹⁰ = 21304077761 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 21304078785.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 562290 + ... + 598980.

It is an arithmetic number, because the mean of its divisors is an integer number (356646240).

Almost surely, 2^21304078785 is an apocalyptic number.

It is an amenable number.

21304078785 is an abundant number, since it is smaller than the sum of its proper divisors (24346639935).

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

21304078785 is a wasteful number, since it uses less digits than its factorization.

21304078785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36756 (or 36750 counting only the distinct ones).

The product of its (nonzero) digits is 376320, while the sum is 45.

The spelling of 21304078785 in words is "twenty-one billion, three hundred four million, seventy-eight thousand, seven hundred eighty-five".