309387813840 has 960 divisors, whose sum is σ = 1316867715072. Its totient is φ = 65965363200.

The previous prime is 309387813811. The next prime is 309387813857. The reversal of 309387813840 is 48318783903.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 128322235 + ... + 128324645.

Almost surely, 2^309387813840 is an apocalyptic number.

309387813840 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 309387813840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (658433857536).

309387813840 is an abundant number, since it is smaller than the sum of its proper divisors (1007479901232).

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

309387813840 is a wasteful number, since it uses less digits than its factorization.

309387813840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2510 (or 2492 counting only the distinct ones).

The product of its (nonzero) digits is 3483648, while the sum is 54.

The spelling of 309387813840 in words is "three hundred nine billion, three hundred eighty-seven million, eight hundred thirteen thousand, eight hundred forty".