7997987 has 4 divisors (see below), whose sum is σ = 8024016. Its totient is φ = 7971960.

The previous prime is 7997971. The next prime is 7997989. The reversal of 7997987 is 7897997.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7897997 = 1511 ⋅5227.

It is a cyclic number.

It is not a de Polignac number, because 7997987 - 2⁴ = 7997971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7997989) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12548 + ... + 13169.

It is an arithmetic number, because the mean of its divisors is an integer number (2006004).

Almost surely, 2^7997987 is an apocalyptic number.

7997987 is a deficient number, since it is larger than the sum of its proper divisors (26029).

7997987 is a wasteful number, since it uses less digits than its factorization.

7997987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26028.

The product of its digits is 2000376, while the sum is 56.

The square root of 7997987 is about 2828.0712508705. The cubic root of 7997987 is about 199.9832235928.

The spelling of 7997987 in words is "seven million, nine hundred ninety-seven thousand, nine hundred eighty-seven".