309990240 has 576 divisors, whose sum is σ = 1347300864. Its totient is φ = 65691648.

The previous prime is 309990221. The next prime is 309990259. The reversal of 309990240 is 42099903.

It is an interprime number because it is at equal distance from previous prime (309990221) and next prime (309990259).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 309990195 and 309990204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4626687 + ... + 4626753.

It is an arithmetic number, because the mean of its divisors is an integer number (2339064).

Almost surely, 2^309990240 is an apocalyptic number.

309990240 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 309990240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (673650432).

309990240 is an abundant number, since it is smaller than the sum of its proper divisors (1037310624).

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

309990240 is a wasteful number, since it uses less digits than its factorization.

309990240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121 (or 101 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 36.

The square root of 309990240 is about 17606.5396941023. The cubic root of 309990240 is about 676.7828424804.

It can be divided in two parts, 3099 and 90240, that added together give a palindrome (93339).

The spelling of 309990240 in words is "three hundred nine million, nine hundred ninety thousand, two hundred forty".