15977945 has 4 divisors (see below), whose sum is σ = 19173540. Its totient is φ = 12782352.

The previous prime is 15977933. The next prime is 15977957. The reversal of 15977945 is 54977951.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (15977933) and next prime (15977957).

It can be written as a sum of positive squares in 2 ways, for example, as 5583769 + 10394176 = 2363^2 + 3224^2 .

It is a cyclic number.

It is not a de Polignac number, because 15977945 - 2¹² = 15973849 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 15977945.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1597790 + ... + 1597799.

It is an arithmetic number, because the mean of its divisors is an integer number (4793385).

Almost surely, 2^15977945 is an apocalyptic number.

It is an amenable number.

15977945 is a deficient number, since it is larger than the sum of its proper divisors (3195595).

15977945 is an equidigital number, since it uses as much as digits as its factorization.

15977945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3195594.

The product of its digits is 396900, while the sum is 47.

The square root of 15977945 is about 3997.2421742997. The cubic root of 15977945 is about 251.8683752442.

The spelling of 15977945 in words is "fifteen million, nine hundred seventy-seven thousand, nine hundred forty-five".