145172391 has 32 divisors (see below), whose sum is σ = 242296320. Its totient is φ = 75268224.

The previous prime is 145172387. The next prime is 145172393. The reversal of 145172391 is 193271541.

It is not a de Polignac number, because 145172391 - 2² = 145172387 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (145172393) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11601 + ... + 20613.

It is an arithmetic number, because the mean of its divisors is an integer number (7571760).

Almost surely, 2^145172391 is an apocalyptic number.

145172391 is a deficient number, since it is larger than the sum of its proper divisors (97123929).

145172391 is a wasteful number, since it uses less digits than its factorization.

145172391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9095.

The product of its digits is 7560, while the sum is 33.

The square root of 145172391 is about 12048.7505991285. The cubic root of 145172391 is about 525.5669050850.

The spelling of 145172391 in words is "one hundred forty-five million, one hundred seventy-two thousand, three hundred ninety-one".