21874451 has 2 divisors, whose sum is σ = 21874452. Its totient is φ = 21874450.

The previous prime is 21874421. The next prime is 21874471. The reversal of 21874451 is 15447812.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21874451 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21874421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10937225 + 10937226.

It is an arithmetic number, because the mean of its divisors is an integer number (10937226).

Almost surely, 2^21874451 is an apocalyptic number.

21874451 is a deficient number, since it is larger than the sum of its proper divisors (1).

21874451 is an equidigital number, since it uses as much as digits as its factorization.

21874451 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8960, while the sum is 32.

The square root of 21874451 is about 4677.0130425305. The cubic root of 21874451 is about 279.6698958428.

The spelling of 21874451 in words is "twenty-one million, eight hundred seventy-four thousand, four hundred fifty-one".