1231844161 has 4 divisors (see below), whose sum is σ = 1233240112. Its totient is φ = 1230448212.

The previous prime is 1231844153. The next prime is 1231844171. The reversal of 1231844161 is 1614481321.

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: 1614481321 = 509 ⋅3171869.

It is a cyclic number.

It is not a de Polignac number, because 1231844161 - 2³ = 1231844153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1231844171) 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, 696651 + ... + 698416.

It is an arithmetic number, because the mean of its divisors is an integer number (308310028).

Almost surely, 2^1231844161 is an apocalyptic number.

It is an amenable number.

1231844161 is a deficient number, since it is larger than the sum of its proper divisors (1395951).

1231844161 is an equidigital number, since it uses as much as digits as its factorization.

1231844161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1395950.

The product of its digits is 4608, while the sum is 31.

The square root of 1231844161 is about 35097.6375415782. The cubic root of 1231844161 is about 1071.9764793166.

The spelling of 1231844161 in words is "one billion, two hundred thirty-one million, eight hundred forty-four thousand, one hundred sixty-one".