1977992 has 8 divisors (see below), whose sum is σ = 3708750. Its totient is φ = 988992.

The previous prime is 1977991. The next prime is 1978021. The reversal of 1977992 is 2997791.

1977992 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 1976836 + 1156 = 1406^2 + 34^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (1977991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123617 + ... + 123632.

2^1977992 is an apocalyptic number.

It is an amenable number.

1977992 is a deficient number, since it is larger than the sum of its proper divisors (1730758).

1977992 is a wasteful number, since it uses less digits than its factorization.

1977992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247255 (or 247251 counting only the distinct ones).

The product of its digits is 71442, while the sum is 44.

The square root of 1977992 is about 1406.4110352241. The cubic root of 1977992 is about 125.5282603829.

The spelling of 1977992 in words is "one million, nine hundred seventy-seven thousand, nine hundred ninety-two".