1291877257 has 16 divisors (see below), whose sum is σ = 1422676224. Its totient is φ = 1163344000.

The previous prime is 1291877227. The next prime is 1291877269. The reversal of 1291877257 is 7527781921.

It is a cyclic number.

It is not a de Polignac number, because 1291877257 - 2⁷ = 1291877129 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1291877257.

It is not an unprimeable number, because it can be changed into a prime (1291877207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1372407 + ... + 1373347.

It is an arithmetic number, because the mean of its divisors is an integer number (88917264).

Almost surely, 2^1291877257 is an apocalyptic number.

It is an amenable number.

1291877257 is a deficient number, since it is larger than the sum of its proper divisors (130798967).

1291877257 is a wasteful number, since it uses less digits than its factorization.

1291877257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2000.

The product of its digits is 493920, while the sum is 49.

The square root of 1291877257 is about 35942.6940698663. The cubic root of 1291877257 is about 1089.1150286770.

The spelling of 1291877257 in words is "one billion, two hundred ninety-one million, eight hundred seventy-seven thousand, two hundred fifty-seven".