145831931 has 4 divisors (see below), whose sum is σ = 166665072. Its totient is φ = 124998792.

The previous prime is 145831927. The next prime is 145831993. The reversal of 145831931 is 139138541.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 145831931 - 2² = 145831927 is a prime.

It is a super-2 number, since 2×145831931² = 42533904198377522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 145831891 and 145831900.

It is not an unprimeable number, because it can be changed into a prime (145831901) 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, 10416560 + ... + 10416573.

It is an arithmetic number, because the mean of its divisors is an integer number (41666268).

Almost surely, 2^145831931 is an apocalyptic number.

145831931 is a deficient number, since it is larger than the sum of its proper divisors (20833141).

145831931 is an equidigital number, since it uses as much as digits as its factorization.

145831931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20833140.

The product of its digits is 12960, while the sum is 35.

The square root of 145831931 is about 12076.0892262355. The cubic root of 145831931 is about 526.3616126295.

The spelling of 145831931 in words is "one hundred forty-five million, eight hundred thirty-one thousand, nine hundred thirty-one".