1291890863 has 8 divisors (see below), whose sum is σ = 1307496960. Its totient is φ = 1276369920.

The previous prime is 1291890763. The next prime is 1291890889. The reversal of 1291890863 is 3680981921.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1291890863 - 2²² = 1287696559 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 (1291890263) 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 7 ways as a sum of consecutive naturals, for example, 9503 + ... + 51711.

It is an arithmetic number, because the mean of its divisors is an integer number (163437120).

Almost surely, 2^1291890863 is an apocalyptic number.

1291890863 is a deficient number, since it is larger than the sum of its proper divisors (15606097).

1291890863 is a wasteful number, since it uses less digits than its factorization.

1291890863 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42577.

The product of its (nonzero) digits is 186624, while the sum is 47.

The square root of 1291890863 is about 35942.8833428817. The cubic root of 1291890863 is about 1089.1188521690.

The spelling of 1291890863 in words is "one billion, two hundred ninety-one million, eight hundred ninety thousand, eight hundred sixty-three".