21462491 has 2 divisors, whose sum is σ = 21462492. Its totient is φ = 21462490.

The previous prime is 21462487. The next prime is 21462521. The reversal of 21462491 is 19426412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21462491 - 2² = 21462487 is a prime.

It is not a weakly prime, because it can be changed into another prime (21462401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10731245 + 10731246.

It is an arithmetic number, because the mean of its divisors is an integer number (10731246).

Almost surely, 2^21462491 is an apocalyptic number.

21462491 is a deficient number, since it is larger than the sum of its proper divisors (1).

21462491 is an equidigital number, since it uses as much as digits as its factorization.

21462491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3456, while the sum is 29.

The square root of 21462491 is about 4632.7627826169. The cubic root of 21462491 is about 277.9030897655.

The spelling of 21462491 in words is "twenty-one million, four hundred sixty-two thousand, four hundred ninety-one".