21154256271 has 32 divisors (see below), whose sum is σ = 33029932800. Its totient is φ = 13344043680.

The previous prime is 21154256267. The next prime is 21154256293. The reversal of 21154256271 is 17265245112.

21154256271 is a `hidden beast` number, since 2 + 1 + 1 + 5 + 4 + 25 + 627 + 1 = 666.

It is not a de Polignac number, because 21154256271 - 2² = 21154256267 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21154256261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 396060 + ... + 446286.

It is an arithmetic number, because the mean of its divisors is an integer number (1032185400).

Almost surely, 2^21154256271 is an apocalyptic number.

21154256271 is a deficient number, since it is larger than the sum of its proper divisors (11875676529).

21154256271 is a wasteful number, since it uses less digits than its factorization.

21154256271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51076 (or 51070 counting only the distinct ones).

The product of its digits is 33600, while the sum is 36.

The spelling of 21154256271 in words is "twenty-one billion, one hundred fifty-four million, two hundred fifty-six thousand, two hundred seventy-one".