21247658267 has 32 divisors (see below), whose sum is σ = 25654786560. Its totient is φ = 17358865920.

The previous prime is 21247658249. The next prime is 21247658269. The reversal of 21247658267 is 76285674212.

It is not a de Polignac number, because 21247658267 - 2¹⁰ = 21247657243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21247658269) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2632484 + ... + 2640542.

It is an arithmetic number, because the mean of its divisors is an integer number (801712080).

Almost surely, 2^21247658267 is an apocalyptic number.

21247658267 is a deficient number, since it is larger than the sum of its proper divisors (4407128293).

21247658267 is a wasteful number, since it uses less digits than its factorization.

21247658267 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8723.

The product of its digits is 2257920, while the sum is 50.

The spelling of 21247658267 in words is "twenty-one billion, two hundred forty-seven million, six hundred fifty-eight thousand, two hundred sixty-seven".