21271293778 has 16 divisors (see below), whose sum is σ = 36964598400. Its totient is φ = 8991387936.

The previous prime is 21271293767. The next prime is 21271293811. The reversal of 21271293778 is 87739217212.

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, 10405678 + ... + 10407721.

It is an arithmetic number, because the mean of its divisors is an integer number (2310287400).

Almost surely, 2^21271293778 is an apocalyptic number.

21271293778 is a deficient number, since it is larger than the sum of its proper divisors (15693304622).

21271293778 is a wasteful number, since it uses less digits than its factorization.

21271293778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20813481.

The product of its digits is 592704, while the sum is 49.

The spelling of 21271293778 in words is "twenty-one billion, two hundred seventy-one million, two hundred ninety-three thousand, seven hundred seventy-eight".