145631257 has 4 divisors (see below), whose sum is σ = 153296080. Its totient is φ = 137966436.

The previous prime is 145631191. The next prime is 145631263. The reversal of 145631257 is 752136541.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-145631257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (145631287) 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 3 ways as a sum of consecutive naturals, for example, 3832383 + ... + 3832420.

It is an arithmetic number, because the mean of its divisors is an integer number (38324020).

Almost surely, 2^145631257 is an apocalyptic number.

It is an amenable number.

145631257 is a deficient number, since it is larger than the sum of its proper divisors (7664823).

145631257 is an equidigital number, since it uses as much as digits as its factorization.

145631257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7664822.

The product of its digits is 25200, while the sum is 34.

The square root of 145631257 is about 12067.7776330193. Note that the first 3 decimals coincide. The cubic root of 145631257 is about 526.1200661303.

Adding to 145631257 its reverse (752136541), we get a palindrome (897767798).

The spelling of 145631257 in words is "one hundred forty-five million, six hundred thirty-one thousand, two hundred fifty-seven".