15996581 has 2 divisors, whose sum is σ = 15996582. Its totient is φ = 15996580.

The previous prime is 15996577. The next prime is 15996583. The reversal of 15996581 is 18569951.

15996581 is nontrivially palindromic in base 12 and base 13.

15996581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14945956 + 1050625 = 3866^2 + 1025^2 .

It is a cyclic number.

It is not a de Polignac number, because 15996581 - 2² = 15996577 is a prime.

It is a super-2 number, since 2×15996581² = 511781207379122, which contains 22 as substring.

Together with 15996583, 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 (15996583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7998290 + 7998291.

It is an arithmetic number, because the mean of its divisors is an integer number (7998291).

Almost surely, 2^15996581 is an apocalyptic number.

It is an amenable number.

15996581 is a deficient number, since it is larger than the sum of its proper divisors (1).

15996581 is an equidigital number, since it uses as much as digits as its factorization.

15996581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 97200, while the sum is 44.

The square root of 15996581 is about 3999.5726021664. The cubic root of 15996581 is about 251.9662600751.

The spelling of 15996581 in words is "fifteen million, nine hundred ninety-six thousand, five hundred eighty-one".