1279900961 has 4 divisors (see below), whose sum is σ = 1280160000. Its totient is φ = 1279641924.

The previous prime is 1279900943. The next prime is 1279900967. The reversal of 1279900961 is 1690099721.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1279900961 - 2¹⁸ = 1279638817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1279900967) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121961 + ... + 132038.

It is an arithmetic number, because the mean of its divisors is an integer number (320040000).

Almost surely, 2^1279900961 is an apocalyptic number.

It is an amenable number.

1279900961 is a deficient number, since it is larger than the sum of its proper divisors (259039).

1279900961 is an equidigital number, since it uses as much as digits as its factorization.

1279900961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259038.

The product of its (nonzero) digits is 61236, while the sum is 44.

The square root of 1279900961 is about 35775.7035011193. The cubic root of 1279900961 is about 1085.7390424567.

The spelling of 1279900961 in words is "one billion, two hundred seventy-nine million, nine hundred thousand, nine hundred sixty-one".