1231307881 has 4 divisors (see below), whose sum is σ = 1259942992. Its totient is φ = 1202672772.

The previous prime is 1231307873. The next prime is 1231307887. The reversal of 1231307881 is 1887031321.

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 1231307881 - 2³ = 1231307873 is a prime.

It is a super-2 number, since 2×1231307881² = 3032238195625420322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1231307887) 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, 14317491 + ... + 14317576.

It is an arithmetic number, because the mean of its divisors is an integer number (314985748).

Almost surely, 2^1231307881 is an apocalyptic number.

It is an amenable number.

1231307881 is a deficient number, since it is larger than the sum of its proper divisors (28635111).

1231307881 is an equidigital number, since it uses as much as digits as its factorization.

1231307881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28635110.

The product of its (nonzero) digits is 8064, while the sum is 34.

The square root of 1231307881 is about 35089.9968794527. The cubic root of 1231307881 is about 1071.8208960567.

The spelling of 1231307881 in words is "one billion, two hundred thirty-one million, three hundred seven thousand, eight hundred eighty-one".