1291883881 has 2 divisors, whose sum is σ = 1291883882. Its totient is φ = 1291883880.

The previous prime is 1291883869. The next prime is 1291883899. The reversal of 1291883881 is 1883881921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1246725481 + 45158400 = 35309^2 + 6720^2 .

It is a cyclic number.

It is not a de Polignac number, because 1291883881 - 2²³ = 1283495273 is a prime.

It is a super-2 number, since 2×1291883881² = 3337927923975244322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1291883081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 645941940 + 645941941.

It is an arithmetic number, because the mean of its divisors is an integer number (645941941).

Almost surely, 2^1291883881 is an apocalyptic number.

It is an amenable number.

1291883881 is a deficient number, since it is larger than the sum of its proper divisors (1).

1291883881 is an equidigital number, since it uses as much as digits as its factorization.

1291883881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 221184, while the sum is 49.

The square root of 1291883881 is about 35942.7862164301. The cubic root of 1291883881 is about 1089.1168901246.

The spelling of 1291883881 in words is "one billion, two hundred ninety-one million, eight hundred eighty-three thousand, eight hundred eighty-one".