7977981 has 16 divisors (see below), whose sum is σ = 12287808. Its totient is φ = 4550400.

The previous prime is 7977971. The next prime is 7977989. The reversal of 7977981 is 1897797.

It is not a de Polignac number, because 7977981 - 2¹⁵ = 7945213 is a prime.

It is a super-2 number, since 2×7977981² = 127296361672722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 7977981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7977989) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6550 + ... + 7671.

It is an arithmetic number, because the mean of its divisors is an integer number (767988).

Almost surely, 2^7977981 is an apocalyptic number.

It is an amenable number.

7977981 is a deficient number, since it is larger than the sum of its proper divisors (4309827).

7977981 is a wasteful number, since it uses less digits than its factorization.

7977981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14252.

The product of its digits is 222264, while the sum is 48.

The square root of 7977981 is about 2824.5319966324. The cubic root of 7977981 is about 199.8163397295.

It can be divided in two parts, 797 and 7981, that added together give a palindrome (8778).

The spelling of 7977981 in words is "seven million, nine hundred seventy-seven thousand, nine hundred eighty-one".