1280695631 has 2 divisors, whose sum is σ = 1280695632. Its totient is φ = 1280695630.

The previous prime is 1280695613. The next prime is 1280695681. The reversal of 1280695631 is 1365960821.

Together with previous prime (1280695613) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1280695631 - 2⁶ = 1280695567 is a prime.

It is a super-2 number, since 2×1280695631² = 3280362598524976322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1280695681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 640347815 + 640347816.

It is an arithmetic number, because the mean of its divisors is an integer number (640347816).

Almost surely, 2^1280695631 is an apocalyptic number.

1280695631 is a deficient number, since it is larger than the sum of its proper divisors (1).

1280695631 is an equidigital number, since it uses as much as digits as its factorization.

1280695631 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 77760, while the sum is 41.

The square root of 1280695631 is about 35786.8080582776. The cubic root of 1280695631 is about 1085.9637019592.

The spelling of 1280695631 in words is "one billion, two hundred eighty million, six hundred ninety-five thousand, six hundred thirty-one".