309213040 has 40 divisors (see below), whose sum is σ = 729663120. Its totient is φ = 121837056.

The previous prime is 309213007. The next prime is 309213061. The reversal of 309213040 is 40312903.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×309213040² = 191225408212083200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23485 + ... + 34204.

It is an arithmetic number, because the mean of its divisors is an integer number (18241578).

Almost surely, 2^309213040 is an apocalyptic number.

It is an amenable number.

309213040 is an abundant number, since it is smaller than the sum of its proper divisors (420450080).

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

309213040 is a wasteful number, since it uses less digits than its factorization.

309213040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57769 (or 57763 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 22.

The square root of 309213040 is about 17584.4544982209. The cubic root of 309213040 is about 676.2167646298.

Adding to 309213040 its reverse (40312903), we get a palindrome (349525943).

The spelling of 309213040 in words is "three hundred nine million, two hundred thirteen thousand, forty".