21263468251 has 8 divisors (see below), whose sum is σ = 21581852544. Its totient is φ = 20945816640.

The previous prime is 21263468249. The next prime is 21263468273. The reversal of 21263468251 is 15286436212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21263468251 - 2¹ = 21263468249 is a prime.

It is a super-2 number, since 2×21263468251² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21263468231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 124555 + ... + 240916.

It is an arithmetic number, because the mean of its divisors is an integer number (2697731568).

Almost surely, 2^21263468251 is an apocalyptic number.

21263468251 is a deficient number, since it is larger than the sum of its proper divisors (318384293).

21263468251 is an equidigital number, since it uses as much as digits as its factorization.

21263468251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 366341.

The product of its digits is 138240, while the sum is 40.

The spelling of 21263468251 in words is "twenty-one billion, two hundred sixty-three million, four hundred sixty-eight thousand, two hundred fifty-one".