21268200251 has 32 divisors (see below), whose sum is σ = 23400187200. Its totient is φ = 19248316416.

The previous prime is 21268200199. The next prime is 21268200263. The reversal of 21268200251 is 15200286212.

It is not a de Polignac number, because 21268200251 - 2²² = 21264005947 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21268205251) 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, 24085856 + ... + 24086738.

It is an arithmetic number, because the mean of its divisors is an integer number (731255850).

Almost surely, 2^21268200251 is an apocalyptic number.

21268200251 is a deficient number, since it is larger than the sum of its proper divisors (2131986949).

21268200251 is a wasteful number, since it uses less digits than its factorization.

21268200251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1343.

The product of its (nonzero) digits is 3840, while the sum is 29.

Adding to 21268200251 its reverse (15200286212), we get a palindrome (36468486463).

The spelling of 21268200251 in words is "twenty-one billion, two hundred sixty-eight million, two hundred thousand, two hundred fifty-one".