7977858440 has 32 divisors (see below), whose sum is σ = 17954758080. Its totient is φ = 3190329792.

The previous prime is 7977858431. The next prime is 7977858467. The reversal of 7977858440 is 448587797.

It is a self number, because there is not a number n which added to its sum of digits gives 7977858440.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 148037 + ... + 194603.

It is an arithmetic number, because the mean of its divisors is an integer number (561086190).

Almost surely, 2^7977858440 is an apocalyptic number.

It is an amenable number.

7977858440 is an abundant number, since it is smaller than the sum of its proper divisors (9976899640).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7977858440 is a wasteful number, since it uses less digits than its factorization.

7977858440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50861 (or 50857 counting only the distinct ones).

The product of its (nonzero) digits is 15805440, while the sum is 59.

The square root of 7977858440 is about 89318.8582551300. The cubic root of 7977858440 is about 1998.1531651254.

The spelling of 7977858440 in words is "seven billion, nine hundred seventy-seven million, eight hundred fifty-eight thousand, four hundred forty".