1913878513 has 12 divisors (see below), whose sum is σ = 2046080092. Its totient is φ = 1789781760.

The previous prime is 1913878511. The next prime is 1913878537. The reversal of 1913878513 is 3158783191.

It can be written as a sum of positive squares in 6 ways, for example, as 20584369 + 1893294144 = 4537^2 + 43512^2 .

It is not a de Polignac number, because 1913878513 - 2¹ = 1913878511 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1913878511) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 24283 + ... + 66463.

Almost surely, 2^1913878513 is an apocalyptic number.

It is an amenable number.

1913878513 is a deficient number, since it is larger than the sum of its proper divisors (132201579).

1913878513 is a wasteful number, since it uses less digits than its factorization.

1913878513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42372 (or 42355 counting only the distinct ones).

The product of its digits is 181440, while the sum is 46.

The square root of 1913878513 is about 43747.8972408960. The cubic root of 1913878513 is about 1241.5707014182.

The spelling of 1913878513 in words is "one billion, nine hundred thirteen million, eight hundred seventy-eight thousand, five hundred thirteen".