21364406784 has 120 divisors (see below), whose sum is σ = 70467677280. Its totient is φ = 6104107008.

The previous prime is 21364406779. The next prime is 21364406827. The reversal of 21364406784 is 48760446312.

21364406784 is a `hidden beast` number, since 2 + 136 + 440 + 6 + 78 + 4 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 298914 + ... + 363425.

It is an arithmetic number, because the mean of its divisors is an integer number (587230644).

Almost surely, 2^21364406784 is an apocalyptic number.

21364406784 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21364406784 is an abundant number, since it is smaller than the sum of its proper divisors (49103270496).

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

21364406784 is an equidigital number, since it uses as much as digits as its factorization.

21364406784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 662370 (or 662351 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 45.

The spelling of 21364406784 in words is "twenty-one billion, three hundred sixty-four million, four hundred six thousand, seven hundred eighty-four".