21876451 has 2 divisors, whose sum is σ = 21876452. Its totient is φ = 21876450.

The previous prime is 21876419. The next prime is 21876457. The reversal of 21876451 is 15467812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21876451 - 2⁵ = 21876419 is a prime.

It is not a weakly prime, because it can be changed into another prime (21876457) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10938225 + 10938226.

It is an arithmetic number, because the mean of its divisors is an integer number (10938226).

Almost surely, 2^21876451 is an apocalyptic number.

21876451 is a deficient number, since it is larger than the sum of its proper divisors (1).

21876451 is an equidigital number, since it uses as much as digits as its factorization.

21876451 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13440, while the sum is 34.

The square root of 21876451 is about 4677.2268493200. The cubic root of 21876451 is about 279.6784190699.

The spelling of 21876451 in words is "twenty-one million, eight hundred seventy-six thousand, four hundred fifty-one".