21311310394 has 16 divisors (see below), whose sum is σ = 35815569696. Its totient is φ = 9425149200.

The previous prime is 21311310389. The next prime is 21311310401. The reversal of 21311310394 is 49301311312.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13089672 + ... + 13091299.

It is an arithmetic number, because the mean of its divisors is an integer number (2238473106).

Almost surely, 2^21311310394 is an apocalyptic number.

21311310394 is a deficient number, since it is larger than the sum of its proper divisors (14504259302).

21311310394 is a wasteful number, since it uses less digits than its factorization.

21311310394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26181021.

The product of its (nonzero) digits is 1944, while the sum is 28.

It can be divided in two parts, 21311 and 310394, that added together give a triangular number (331705 = T₈₁₄).

The spelling of 21311310394 in words is "twenty-one billion, three hundred eleven million, three hundred ten thousand, three hundred ninety-four".