1977994937 has 4 divisors (see below), whose sum is σ = 1978858356. Its totient is φ = 1977131520.

The previous prime is 1977994919. The next prime is 1977995011. The reversal of 1977994937 is 7394997791.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7394997791 = 401 ⋅18441391.

It can be written as a sum of positive squares in 2 ways, for example, as 1003368976 + 974625961 = 31676^2 + 31219^2 .

It is a cyclic number.

It is not a de Polignac number, because 1977994937 - 2⁶ = 1977994873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1977994537) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 428264 + ... + 432857.

It is an arithmetic number, because the mean of its divisors is an integer number (494714589).

Almost surely, 2^1977994937 is an apocalyptic number.

It is an amenable number.

1977994937 is a deficient number, since it is larger than the sum of its proper divisors (863419).

1977994937 is an equidigital number, since it uses as much as digits as its factorization.

1977994937 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 863418.

The product of its digits is 27005076, while the sum is 65.

The square root of 1977994937 is about 44474.6549958513. The cubic root of 1977994937 is about 1255.2832251260.

The spelling of 1977994937 in words is "one billion, nine hundred seventy-seven million, nine hundred ninety-four thousand, nine hundred thirty-seven".