1977317845 has 4 divisors (see below), whose sum is σ = 2372781420. Its totient is φ = 1581854272.

The previous prime is 1977317833. The next prime is 1977317911. The reversal of 1977317845 is 5487137791.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1071187441 + 906130404 = 32729^2 + 30102^2 .

It is a cyclic number.

It is not a de Polignac number, because 1977317845 - 2⁵ = 1977317813 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1977317792 and 1977317801.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 197731780 + ... + 197731789.

It is an arithmetic number, because the mean of its divisors is an integer number (593195355).

Almost surely, 2^1977317845 is an apocalyptic number.

It is an amenable number.

1977317845 is a deficient number, since it is larger than the sum of its proper divisors (395463575).

1977317845 is an equidigital number, since it uses as much as digits as its factorization.

1977317845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 395463574.

The product of its digits is 1481760, while the sum is 52.

The square root of 1977317845 is about 44467.0422335464. The cubic root of 1977317845 is about 1255.1399758160.

The spelling of 1977317845 in words is "one billion, nine hundred seventy-seven million, three hundred seventeen thousand, eight hundred forty-five".