7977711640 has 64 divisors (see below), whose sum is σ = 18907480800. Its totient is φ = 3021069312.

The previous prime is 7977711619. The next prime is 7977711649. The reversal of 7977711640 is 461177797.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7977711649) 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, 1557724 + ... + 1562836.

Almost surely, 2^7977711640 is an apocalyptic number.

It is an amenable number.

7977711640 is an abundant number, since it is smaller than the sum of its proper divisors (10929769160).

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

7977711640 is a wasteful number, since it uses less digits than its factorization.

7977711640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7196 (or 7192 counting only the distinct ones).

The product of its (nonzero) digits is 518616, while the sum is 49.

The square root of 7977711640 is about 89318.0364764027. The cubic root of 7977711640 is about 1998.1409090926.

The spelling of 7977711640 in words is "seven billion, nine hundred seventy-seven million, seven hundred eleven thousand, six hundred forty".