145541317991 has 4 divisors (see below), whose sum is σ = 145550634000. Its totient is φ = 145532001984.

The previous prime is 145541317927. The next prime is 145541317997. The reversal of 145541317991 is 199713145541.

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 145541317991 - 2⁶ = 145541317927 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 (145541317997) 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, 4634531 + ... + 4665828.

It is an arithmetic number, because the mean of its divisors is an integer number (36387658500).

Almost surely, 2^145541317991 is an apocalyptic number.

145541317991 is a deficient number, since it is larger than the sum of its proper divisors (9316009).

145541317991 is an equidigital number, since it uses as much as digits as its factorization.

145541317991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9316008.

The product of its digits is 680400, while the sum is 50.

The spelling of 145541317991 in words is "one hundred forty-five billion, five hundred forty-one million, three hundred seventeen thousand, nine hundred ninety-one".