1231379961 has 16 divisors (see below), whose sum is σ = 1885824000. Its totient is φ = 700107408.

The previous prime is 1231379959. The next prime is 1231380001. The reversal of 1231379961 is 1699731321.

It is not a de Polignac number, because 1231379961 - 2¹ = 1231379959 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1231329961) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 143151 + ... + 151508.

It is an arithmetic number, because the mean of its divisors is an integer number (117864000).

Almost surely, 2^1231379961 is an apocalyptic number.

It is an amenable number.

1231379961 is a deficient number, since it is larger than the sum of its proper divisors (654444039).

1231379961 is a wasteful number, since it uses less digits than its factorization.

1231379961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 294868.

The product of its digits is 61236, while the sum is 42.

The square root of 1231379961 is about 35091.0239377537. The cubic root of 1231379961 is about 1071.8418102256.

The spelling of 1231379961 in words is "one billion, two hundred thirty-one million, three hundred seventy-nine thousand, nine hundred sixty-one".