21964511 has 2 divisors, whose sum is σ = 21964512. Its totient is φ = 21964510.

The previous prime is 21964507. The next prime is 21964541. The reversal of 21964511 is 11546912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21964511 - 2² = 21964507 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21964541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10982255 + 10982256.

It is an arithmetic number, because the mean of its divisors is an integer number (10982256).

Almost surely, 2^21964511 is an apocalyptic number.

21964511 is a deficient number, since it is larger than the sum of its proper divisors (1).

21964511 is an equidigital number, since it uses as much as digits as its factorization.

21964511 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2160, while the sum is 29.

The square root of 21964511 is about 4686.6310928000. The cubic root of 21964511 is about 280.0531829251.

The spelling of 21964511 in words is "twenty-one million, nine hundred sixty-four thousand, five hundred eleven".