308231813 has 4 divisors (see below), whose sum is σ = 324454560. Its totient is φ = 292009068.

The previous prime is 308231773. The next prime is 308231821. The reversal of 308231813 is 318132803.

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, and also an emirpimes, since its reverse is a distinct semiprime: 318132803 = 23 ⋅13831861.

It is a cyclic number.

It is not a de Polignac number, because 308231813 - 2¹⁶ = 308166277 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (308231843) 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, 8111345 + ... + 8111382.

It is an arithmetic number, because the mean of its divisors is an integer number (81113640).

Almost surely, 2^308231813 is an apocalyptic number.

It is an amenable number.

308231813 is a deficient number, since it is larger than the sum of its proper divisors (16222747).

308231813 is a wasteful number, since it uses less digits than its factorization.

308231813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16222746.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 308231813 is about 17556.5319183488. The cubic root of 308231813 is about 675.5007262206.

The spelling of 308231813 in words is "three hundred eight million, two hundred thirty-one thousand, eight hundred thirteen".