131778923 has 4 divisors (see below), whose sum is σ = 136029888. Its totient is φ = 127527960.

The previous prime is 131778893. The next prime is 131778931. The reversal of 131778923 is 329877131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 329877131 = 179 ⋅1842889.

It is a cyclic number.

It is not a de Polignac number, because 131778923 - 2⁶ = 131778859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131778973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2125436 + ... + 2125497.

It is an arithmetic number, because the mean of its divisors is an integer number (34007472).

Almost surely, 2^131778923 is an apocalyptic number.

131778923 is a deficient number, since it is larger than the sum of its proper divisors (4250965).

131778923 is an equidigital number, since it uses as much as digits as its factorization.

131778923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4250964.

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

The square root of 131778923 is about 11479.5001197787. The cubic root of 131778923 is about 508.8799242774.

The spelling of 131778923 in words is "one hundred thirty-one million, seven hundred seventy-eight thousand, nine hundred twenty-three".