131223645 has 112 divisors (see below), whose sum is σ = 279108480. Its totient is φ = 57946752.

The previous prime is 131223613. The next prime is 131223737. The reversal of 131223645 is 546322131.

131223645 is a `hidden beast` number, since 1 + 3 + 12 + 2 + 3 + 645 = 666.

It is not a de Polignac number, because 131223645 - 2⁵ = 131223613 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 943986 + ... + 944124.

It is an arithmetic number, because the mean of its divisors is an integer number (2492040).

Almost surely, 2^131223645 is an apocalyptic number.

131223645 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

131223645 is an abundant number, since it is smaller than the sum of its proper divisors (147884835).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

131223645 is an equidigital number, since it uses as much as digits as its factorization.

131223645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206 (or 191 counting only the distinct ones).

The product of its digits is 4320, while the sum is 27.

The square root of 131223645 is about 11455.2889531430. The cubic root of 131223645 is about 508.1641607323.

Adding to 131223645 its reverse (546322131), we get a palindrome (677545776).

The spelling of 131223645 in words is "one hundred thirty-one million, two hundred twenty-three thousand, six hundred forty-five".