145117731 has 16 divisors (see below), whose sum is σ = 211432320. Its totient is φ = 87803520.

The previous prime is 145117697. The next prime is 145117747. The reversal of 145117731 is 137711541.

It is not a de Polignac number, because 145117731 - 2²³ = 136729123 is a prime.

It is a super-2 number, since 2×145117731² = 42118311701176722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (145117771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18411 + ... + 25083.

It is an arithmetic number, because the mean of its divisors is an integer number (13214520).

Almost surely, 2^145117731 is an apocalyptic number.

145117731 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

145117731 is a deficient number, since it is larger than the sum of its proper divisors (66314589).

145117731 is a wasteful number, since it uses less digits than its factorization.

145117731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7346.

The product of its digits is 2940, while the sum is 30.

The square root of 145117731 is about 12046.4821005968. The cubic root of 145117731 is about 525.5009350268.

The spelling of 145117731 in words is "one hundred forty-five million, one hundred seventeen thousand, seven hundred thirty-one".