15964661 has 2 divisors, whose sum is σ = 15964662. Its totient is φ = 15964660.

The previous prime is 15964657. The next prime is 15964667. The reversal of 15964661 is 16646951.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15062161 + 902500 = 3881^2 + 950^2 .

It is a cyclic number.

It is not a de Polignac number, because 15964661 - 2² = 15964657 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15964667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7982330 + 7982331.

It is an arithmetic number, because the mean of its divisors is an integer number (7982331).

Almost surely, 2^15964661 is an apocalyptic number.

It is an amenable number.

15964661 is a deficient number, since it is larger than the sum of its proper divisors (1).

15964661 is an equidigital number, since it uses as much as digits as its factorization.

15964661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38880, while the sum is 38.

The square root of 15964661 is about 3995.5801831524. The cubic root of 15964661 is about 251.7985551024.

The spelling of 15964661 in words is "fifteen million, nine hundred sixty-four thousand, six hundred sixty-one".