145215531 has 16 divisors (see below), whose sum is σ = 215413120. Its totient is φ = 96684840.

The previous prime is 145215529. The next prime is 145215533. The reversal of 145215531 is 135512541.

It is an interprime number because it is at equal distance from previous prime (145215529) and next prime (145215533).

It is not a de Polignac number, because 145215531 - 2¹ = 145215529 is a prime.

It is a super-2 number, since 2×145215531² = 42175100887223922, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 145215495 and 145215504.

It is not an unprimeable number, because it can be changed into a prime (145215533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20796 + ... + 26886.

It is an arithmetic number, because the mean of its divisors is an integer number (13463320).

Almost surely, 2^145215531 is an apocalyptic number.

145215531 is a deficient number, since it is larger than the sum of its proper divisors (70197589).

145215531 is an equidigital number, since it uses as much as digits as its factorization.

145215531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6983 (or 6977 counting only the distinct ones).

The product of its digits is 3000, while the sum is 27.

The square root of 145215531 is about 12050.5406932635. The cubic root of 145215531 is about 525.6189597735.

The spelling of 145215531 in words is "one hundred forty-five million, two hundred fifteen thousand, five hundred thirty-one".