1231390877 has 4 divisors (see below), whose sum is σ = 1231856640. Its totient is φ = 1230925116.

The previous prime is 1231390873. The next prime is 1231390879. The reversal of 1231390877 is 7780931321.

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, and also an emirpimes, since its reverse is a distinct semiprime: 7780931321 = 2311 ⋅3366911.

It is a cyclic number.

It is not a de Polignac number, because 1231390877 - 2² = 1231390873 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 (1231390873) 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, 228893 + ... + 234210.

It is an arithmetic number, because the mean of its divisors is an integer number (307964160).

Almost surely, 2^1231390877 is an apocalyptic number.

It is an amenable number.

1231390877 is a deficient number, since it is larger than the sum of its proper divisors (465763).

1231390877 is an equidigital number, since it uses as much as digits as its factorization.

1231390877 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 465762.

The product of its (nonzero) digits is 63504, while the sum is 41.

The square root of 1231390877 is about 35091.1794757600. The cubic root of 1231390877 is about 1071.8449774556.

The spelling of 1231390877 in words is "one billion, two hundred thirty-one million, three hundred ninety thousand, eight hundred seventy-seven".