21311330418 has 64 divisors (see below), whose sum is σ = 54164920320. Its totient is φ = 6084349776.

The previous prime is 21311330399. The next prime is 21311330459. The reversal of 21311330418 is 81403311312.

21311330418 is a `hidden beast` number, since 2 + 1 + 311 + 330 + 4 + 18 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 21311330391 and 21311330400.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 496105 + ... + 537347.

It is an arithmetic number, because the mean of its divisors is an integer number (846326880).

Almost surely, 2^21311330418 is an apocalyptic number.

21311330418 is an abundant number, since it is smaller than the sum of its proper divisors (32853589902).

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

21311330418 is a wasteful number, since it uses less digits than its factorization.

21311330418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42628 (or 42622 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The spelling of 21311330418 in words is "twenty-one billion, three hundred eleven million, three hundred thirty thousand, four hundred eighteen".