1977164640 has 672 divisors, whose sum is σ = 8091207936. Its totient is φ = 451630080.

The previous prime is 1977164633. The next prime is 1977164669. The reversal of 1977164640 is 464617791.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 29509887 + ... + 29509953.

It is an arithmetic number, because the mean of its divisors is an integer number (12040488).

Almost surely, 2^1977164640 is an apocalyptic number.

1977164640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1977164640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4045603968).

1977164640 is an abundant number, since it is smaller than the sum of its proper divisors (6114043296).

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

1977164640 is a wasteful number, since it uses less digits than its factorization.

1977164640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134 (or 111 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 45.

The square root of 1977164640 is about 44465.3195198235. The cubic root of 1977164640 is about 1255.1075583863.

The spelling of 1977164640 in words is "one billion, nine hundred seventy-seven million, one hundred sixty-four thousand, six hundred forty".