15977989 has 8 divisors (see below), whose sum is σ = 16651008. Its totient is φ = 15314880.

The previous prime is 15977981. The next prime is 15978023. The reversal of 15977989 is 98977951.

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

It is a cyclic number.

It is not a de Polignac number, because 15977989 - 2³ = 15977981 is a prime.

It is a super-2 number, since 2×15977989² = 510592264968242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15977981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 909 + ... + 5725.

It is an arithmetic number, because the mean of its divisors is an integer number (2081376).

Almost surely, 2^15977989 is an apocalyptic number.

It is an amenable number.

15977989 is a deficient number, since it is larger than the sum of its proper divisors (673019).

15977989 is a wasteful number, since it uses less digits than its factorization.

15977989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4955.

The product of its digits is 1428840, while the sum is 55.

The square root of 15977989 is about 3997.2476780905. The cubic root of 15977989 is about 251.8686064420.

The spelling of 15977989 in words is "fifteen million, nine hundred seventy-seven thousand, nine hundred eighty-nine".