1291831563 has 16 divisors (see below), whose sum is σ = 1879675776. Its totient is φ = 782658240.

The previous prime is 1291831543. The next prime is 1291831573. The reversal of 1291831563 is 3651381921.

It is not a de Polignac number, because 1291831563 - 2⁵ = 1291831531 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1291831523) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 134520 + ... + 143802.

It is an arithmetic number, because the mean of its divisors is an integer number (117479736).

Almost surely, 2^1291831563 is an apocalyptic number.

1291831563 is a deficient number, since it is larger than the sum of its proper divisors (587844213).

1291831563 is a wasteful number, since it uses less digits than its factorization.

1291831563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13514.

The product of its digits is 38880, while the sum is 39.

The square root of 1291831563 is about 35942.0584135077. The cubic root of 1291831563 is about 1089.1021877747.

The spelling of 1291831563 in words is "one billion, two hundred ninety-one million, eight hundred thirty-one thousand, five hundred sixty-three".