145317731 has 4 divisors (see below), whose sum is σ = 156496032. Its totient is φ = 134139432.

The previous prime is 145317713. The next prime is 145317761. The reversal of 145317731 is 137713541.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 137713541 = 7 ⋅19673363.

It is a cyclic number.

It is not a de Polignac number, because 145317731 - 2¹⁰ = 145316707 is a prime.

It is a super-2 number, since 2×145317731² = 42234485885976722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (145317761) 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, 5589131 + ... + 5589156.

It is an arithmetic number, because the mean of its divisors is an integer number (39124008).

Almost surely, 2^145317731 is an apocalyptic number.

145317731 is a deficient number, since it is larger than the sum of its proper divisors (11178301).

145317731 is a wasteful number, since it uses less digits than its factorization.

145317731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11178300.

The product of its digits is 8820, while the sum is 32.

The square root of 145317731 is about 12054.7804210612. The cubic root of 145317731 is about 525.7422378193.

The spelling of 145317731 in words is "one hundred forty-five million, three hundred seventeen thousand, seven hundred thirty-one".