15977972 has 6 divisors (see below), whose sum is σ = 27961458. Its totient is φ = 7988984.

The previous prime is 15977971. The next prime is 15977981. The reversal of 15977972 is 27977951.

It can be written as a sum of positive squares in only one way, i.e., 10797796 + 5180176 = 3286^2 + 2276^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15977971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1997243 + ... + 1997250.

It is an arithmetic number, because the mean of its divisors is an integer number (4660243).

Almost surely, 2^15977972 is an apocalyptic number.

It is an amenable number.

15977972 is a deficient number, since it is larger than the sum of its proper divisors (11983486).

15977972 is a wasteful number, since it uses less digits than its factorization.

15977972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3994497 (or 3994495 counting only the distinct ones).

The product of its digits is 277830, while the sum is 47.

The square root of 15977972 is about 3997.2455516268. The cubic root of 15977972 is about 251.8685171156.

The spelling of 15977972 in words is "fifteen million, nine hundred seventy-seven thousand, nine hundred seventy-two".