309649620 has 72 divisors (see below), whose sum is σ = 1008582624. Its totient is φ = 70776384.

The previous prime is 309649619. The next prime is 309649657. The reversal of 309649620 is 26946903.

It is a happy number.

It is a super-2 number, since 2×309649620² = 191765774332288800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 49722 + ... + 55601.

It is an arithmetic number, because the mean of its divisors is an integer number (14008092).

Almost surely, 2^309649620 is an apocalyptic number.

309649620 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

309649620 is an abundant number, since it is smaller than the sum of its proper divisors (698933004).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

309649620 is a wasteful number, since it uses less digits than its factorization.

309649620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105349 (or 105340 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 39.

The square root of 309649620 is about 17596.8639251430. The cubic root of 309649620 is about 676.5348666538.

The spelling of 309649620 in words is "three hundred nine million, six hundred forty-nine thousand, six hundred twenty".