15751661 has 2 divisors, whose sum is σ = 15751662. Its totient is φ = 15751660.

The previous prime is 15751651. The next prime is 15751663. The reversal of 15751661 is 16615751.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14394436 + 1357225 = 3794^2 + 1165^2 .

It is a cyclic number.

It is not a de Polignac number, because 15751661 - 2⁶ = 15751597 is a prime.

It is a super-2 number, since 2×15751661² = 496229648517842, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 15751663, it forms a pair of twin primes.

It is a Chen 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 (15751663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7875830 + 7875831.

It is an arithmetic number, because the mean of its divisors is an integer number (7875831).

Almost surely, 2^15751661 is an apocalyptic number.

It is an amenable number.

15751661 is a deficient number, since it is larger than the sum of its proper divisors (1).

15751661 is an equidigital number, since it uses as much as digits as its factorization.

15751661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6300, while the sum is 32.

The square root of 15751661 is about 3968.8362274097. The cubic root of 15751661 is about 250.6737081717.

The spelling of 15751661 in words is "fifteen million, seven hundred fifty-one thousand, six hundred sixty-one".