145631321 has 4 divisors (see below), whose sum is σ = 158870544. Its totient is φ = 132392100.

The previous prime is 145631287. The next prime is 145631327. The reversal of 145631321 is 123136541.

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 not a de Polignac number, because 145631321 - 2¹⁰ = 145630297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (145631327) 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, 6619595 + ... + 6619616.

It is an arithmetic number, because the mean of its divisors is an integer number (39717636).

Almost surely, 2^145631321 is an apocalyptic number.

145631321 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

145631321 is a deficient number, since it is larger than the sum of its proper divisors (13239223).

145631321 is a wasteful number, since it uses less digits than its factorization.

145631321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13239222.

The product of its digits is 2160, while the sum is 26.

The square root of 145631321 is about 12067.7802847085. The cubic root of 145631321 is about 526.1201432010.

Adding to 145631321 its reverse (123136541), we get a palindrome (268767862).

The spelling of 145631321 in words is "one hundred forty-five million, six hundred thirty-one thousand, three hundred twenty-one".