15523661 has 2 divisors, whose sum is σ = 15523662. Its totient is φ = 15523660.

The previous prime is 15523657. The next prime is 15523663. The reversal of 15523661 is 16632551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9672100 + 5851561 = 3110^2 + 2419^2 .

It is a cyclic number.

It is not a de Polignac number, because 15523661 - 2² = 15523657 is a prime.

Together with 15523663, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15523663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7761830 + 7761831.

It is an arithmetic number, because the mean of its divisors is an integer number (7761831).

Almost surely, 2^15523661 is an apocalyptic number.

It is an amenable number.

15523661 is a deficient number, since it is larger than the sum of its proper divisors (1).

15523661 is an equidigital number, since it uses as much as digits as its factorization.

15523661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5400, while the sum is 29.

The square root of 15523661 is about 3940.0077411091. The cubic root of 15523661 is about 249.4583526535.

The spelling of 15523661 in words is "fifteen million, five hundred twenty-three thousand, six hundred sixty-one".