15899881 has 2 divisors, whose sum is σ = 15899882. Its totient is φ = 15899880.

The previous prime is 15899867. The next prime is 15899909. The reversal of 15899881 is 18899851.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10989225 + 4910656 = 3315^2 + 2216^2 .

It is a cyclic number.

It is not a de Polignac number, because 15899881 - 2¹⁹ = 15375593 is a prime.

It is a super-2 number, since 2×15899881² = 505612431628322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (15899281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7949940 + 7949941.

It is an arithmetic number, because the mean of its divisors is an integer number (7949941).

Almost surely, 2^15899881 is an apocalyptic number.

It is an amenable number.

15899881 is a deficient number, since it is larger than the sum of its proper divisors (1).

15899881 is an equidigital number, since it uses as much as digits as its factorization.

15899881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 207360, while the sum is 49.

The square root of 15899881 is about 3987.4654857440. The cubic root of 15899881 is about 251.4575180510.

The spelling of 15899881 in words is "fifteen million, eight hundred ninety-nine thousand, eight hundred eighty-one".