1977974640 has 100 divisors (see below), whose sum is σ = 6869821464. Its totient is φ = 527458176.

The previous prime is 1977974597. The next prime is 1977974641. The reversal of 1977974640 is 464797791.

1977974640 is a `hidden beast` number, since 1 + 97 + 7 + 97 + 464 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1977974641) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 146142 + ... + 159101.

Almost surely, 2^1977974640 is an apocalyptic number.

1977974640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1977974640 is an abundant number, since it is smaller than the sum of its proper divisors (4891846824).

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

1977974640 is a wasteful number, since it uses less digits than its factorization.

1977974640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 305268 (or 305253 counting only the distinct ones).

The product of its (nonzero) digits is 2667168, while the sum is 54.

The square root of 1977974640 is about 44474.4268091226. The cubic root of 1977974640 is about 1255.2789314563.

The spelling of 1977974640 in words is "one billion, nine hundred seventy-seven million, nine hundred seventy-four thousand, six hundred forty".