15913985 has 8 divisors (see below), whose sum is σ = 19410216. Its totient is φ = 12522240.

The previous prime is 15913981. The next prime is 15913987. The reversal of 15913985 is 58931951.

It can be written as a sum of positive squares in 4 ways, for example, as 1948816 + 13965169 = 1396^2 + 3737^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 15913985 - 2² = 15913981 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15913981) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25784 + ... + 26393.

It is an arithmetic number, because the mean of its divisors is an integer number (2426277).

Almost surely, 2^15913985 is an apocalyptic number.

It is an amenable number.

15913985 is a deficient number, since it is larger than the sum of its proper divisors (3496231).

15913985 is an equidigital number, since it uses as much as digits as its factorization.

15913985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52243.

The product of its digits is 48600, while the sum is 41.

The square root of 15913985 is about 3989.2336356749. The cubic root of 15913985 is about 251.5318479300.

The spelling of 15913985 in words is "fifteen million, nine hundred thirteen thousand, nine hundred eighty-five".