21174961 has 2 divisors, whose sum is σ = 21174962. Its totient is φ = 21174960.

The previous prime is 21174941. The next prime is 21174977. The reversal of 21174961 is 16947112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14205361 + 6969600 = 3769^2 + 2640^2 .

It is a cyclic number.

It is not a de Polignac number, because 21174961 - 2⁵ = 21174929 is a prime.

It is not a weakly prime, because it can be changed into another prime (21174941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10587480 + 10587481.

It is an arithmetic number, because the mean of its divisors is an integer number (10587481).

Almost surely, 2^21174961 is an apocalyptic number.

It is an amenable number.

21174961 is a deficient number, since it is larger than the sum of its proper divisors (1).

21174961 is an equidigital number, since it uses as much as digits as its factorization.

21174961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3024, while the sum is 31.

The square root of 21174961 is about 4601.6259083068. The cubic root of 21174961 is about 276.6564966181.

The spelling of 21174961 in words is "twenty-one million, one hundred seventy-four thousand, nine hundred sixty-one".