1378661157 has 6 divisors (see below), whose sum is σ = 1991399462. Its totient is φ = 919107432.

The previous prime is 1378661149. The next prime is 1378661191. The reversal of 1378661157 is 7511668731.

It can be written as a sum of positive squares in only one way, i.e., 1372035681 + 6625476 = 37041^2 + 2574^2 .

It is not a de Polignac number, because 1378661157 - 2³ = 1378661149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1378661957) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 76592278 + ... + 76592295.

Almost surely, 2^1378661157 is an apocalyptic number.

It is an amenable number.

1378661157 is a deficient number, since it is larger than the sum of its proper divisors (612738305).

1378661157 is a wasteful number, since it uses less digits than its factorization.

1378661157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153184579 (or 153184576 counting only the distinct ones).

The product of its digits is 211680, while the sum is 45.

The square root of 1378661157 is about 37130.3266481726. The cubic root of 1378661157 is about 1112.9761209437.

The spelling of 1378661157 in words is "one billion, three hundred seventy-eight million, six hundred sixty-one thousand, one hundred fifty-seven".