1977238686 has 32 divisors (see below), whose sum is σ = 4407471360. Its totient is φ = 587661696.

The previous prime is 1977238673. The next prime is 1977238733. The reversal of 1977238686 is 6868327791.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 508186 + ... + 512061.

It is an arithmetic number, because the mean of its divisors is an integer number (137733480).

Almost surely, 2^1977238686 is an apocalyptic number.

1977238686 is an abundant number, since it is smaller than the sum of its proper divisors (2430232674).

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

1977238686 is a wasteful number, since it uses less digits than its factorization.

1977238686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1020288.

The product of its digits is 6096384, while the sum is 57.

The square root of 1977238686 is about 44466.1521384525. The cubic root of 1977238686 is about 1255.1232263673.

The spelling of 1977238686 in words is "one billion, nine hundred seventy-seven million, two hundred thirty-eight thousand, six hundred eighty-six".