1977378553 has 4 divisors (see below), whose sum is σ = 1990649700. Its totient is φ = 1964107408.

The previous prime is 1977378547. The next prime is 1977378587. The reversal of 1977378553 is 3558737791.

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 768564729 + 1208813824 = 27723^2 + 34768^2 .

It is a cyclic number.

It is not a de Polignac number, because 1977378553 - 2⁹ = 1977378041 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1977378494 and 1977378503.

It is not an unprimeable number, because it can be changed into a prime (1977378503) 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, 6635350 + ... + 6635647.

It is an arithmetic number, because the mean of its divisors is an integer number (497662425).

Almost surely, 2^1977378553 is an apocalyptic number.

It is an amenable number.

1977378553 is a deficient number, since it is larger than the sum of its proper divisors (13271147).

1977378553 is a wasteful number, since it uses less digits than its factorization.

1977378553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13271146.

The product of its digits is 5556600, while the sum is 55.

The square root of 1977378553 is about 44467.7248462298. The cubic root of 1977378553 is about 1255.1528208690.

The spelling of 1977378553 in words is "one billion, nine hundred seventy-seven million, three hundred seventy-eight thousand, five hundred fifty-three".