309720704 has 16 divisors (see below), whose sum is σ = 617021970. Its totient is φ = 154860288.

The previous prime is 309720703. The next prime is 309720707. The reversal of 309720704 is 407027903.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 289000000 + 20720704 = 17000^2 + 4552^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is a Harshad number since it is a multiple of its sum of digits (32).

It is not an unprimeable number, because it can be changed into a prime (309720703) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1209719 + ... + 1209974.

Almost surely, 2^309720704 is an apocalyptic number.

It is an amenable number.

309720704 is a deficient number, since it is larger than the sum of its proper divisors (307301266).

309720704 is an equidigital number, since it uses as much as digits as its factorization.

309720704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2419707 (or 2419695 counting only the distinct ones).

The product of its (nonzero) digits is 10584, while the sum is 32.

The square root of 309720704 is about 17598.8836009561. The cubic root of 309720704 is about 676.5866317477.

The spelling of 309720704 in words is "three hundred nine million, seven hundred twenty thousand, seven hundred four".