1977398947 has 2 divisors, whose sum is σ = 1977398948. Its totient is φ = 1977398946.

The previous prime is 1977398923. The next prime is 1977398957. The reversal of 1977398947 is 7498937791.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1977398947 is a prime.

It is not a weakly prime, because it can be changed into another prime (1977398957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 988699473 + 988699474.

It is an arithmetic number, because the mean of its divisors is an integer number (988699474).

Almost surely, 2^1977398947 is an apocalyptic number.

1977398947 is a deficient number, since it is larger than the sum of its proper divisors (1).

1977398947 is an equidigital number, since it uses as much as digits as its factorization.

1977398947 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24004512, while the sum is 64.

The square root of 1977398947 is about 44467.9541580226. The cubic root of 1977398947 is about 1255.1571359252.

The spelling of 1977398947 in words is "one billion, nine hundred seventy-seven million, three hundred ninety-eight thousand, nine hundred forty-seven".