309807381 has 16 divisors (see below), whose sum is σ = 445175360. Its totient is φ = 190512000.

The previous prime is 309807373. The next prime is 309807403. The reversal of 309807381 is 183708903.

It is not a de Polignac number, because 309807381 - 2³ = 309807373 is a prime.

It is a super-2 number, since 2×309807381² = 191961226644158322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (309807341) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 86025 + ... + 89553.

It is an arithmetic number, because the mean of its divisors is an integer number (27823460).

Almost surely, 2^309807381 is an apocalyptic number.

It is an amenable number.

309807381 is a deficient number, since it is larger than the sum of its proper divisors (135367979).

309807381 is a wasteful number, since it uses less digits than its factorization.

309807381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5796.

The product of its (nonzero) digits is 36288, while the sum is 39.

The square root of 309807381 is about 17601.3459996672. The cubic root of 309807381 is about 676.6497413267.

The spelling of 309807381 in words is "three hundred nine million, eight hundred seven thousand, three hundred eighty-one".