21295961 has 2 divisors, whose sum is σ = 21295962. Its totient is φ = 21295960.

The previous prime is 21295913. The next prime is 21295997. The reversal of 21295961 is 16959212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20647936 + 648025 = 4544^2 + 805^2 .

It is a cyclic number.

It is not a de Polignac number, because 21295961 - 2¹⁰ = 21294937 is a prime.

It is not a weakly prime, because it can be changed into another prime (21295361) 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, 10647980 + 10647981.

It is an arithmetic number, because the mean of its divisors is an integer number (10647981).

Almost surely, 2^21295961 is an apocalyptic number.

It is an amenable number.

21295961 is a deficient number, since it is larger than the sum of its proper divisors (1).

21295961 is an equidigital number, since it uses as much as digits as its factorization.

21295961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9720, while the sum is 35.

The square root of 21295961 is about 4614.7547063739. The cubic root of 21295961 is about 277.1824617725.

The spelling of 21295961 in words is "twenty-one million, two hundred ninety-five thousand, nine hundred sixty-one".