145137731 has 4 divisors (see below), whose sum is σ = 145165464. Its totient is φ = 145110000.

The previous prime is 145137719. The next prime is 145137743. The reversal of 145137731 is 137731541.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 137731541 = 1217 ⋅113173.

It is an interprime number because it is at equal distance from previous prime (145137719) and next prime (145137743).

It is a cyclic number.

It is not a de Polignac number, because 145137731 - 2⁶ = 145137667 is a prime.

It is a super-2 number, since 2×145137731² = 42129921919656722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (145137761) 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, 3365 + ... + 17366.

It is an arithmetic number, because the mean of its divisors is an integer number (36291366).

Almost surely, 2^145137731 is an apocalyptic number.

145137731 is a deficient number, since it is larger than the sum of its proper divisors (27733).

145137731 is an equidigital number, since it uses as much as digits as its factorization.

145137731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27732.

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

The square root of 145137731 is about 12047.3121898621. The cubic root of 145137731 is about 525.5250752790.

The spelling of 145137731 in words is "one hundred forty-five million, one hundred thirty-seven thousand, seven hundred thirty-one".