309487491856 has 15 divisors (see below), whose sum is σ = 599636326951. Its totient is φ = 154742633296.

The previous prime is 309487491853. The next prime is 309487491857. The reversal of 309487491856 is 658194784903.

The square root of 309487491856 is 556316.

It is a perfect power (a square), and thus also a powerful number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (309487491853) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2155725 + ... + 2294803.

Almost surely, 2^309487491856 is an apocalyptic number.

309487491856 is the 556316-th square number.

It is an amenable number.

309487491856 is a deficient number, since it is larger than the sum of its proper divisors (290148835095).

309487491856 is an frugal number, since it uses more digits than its factorization.

309487491856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 278166 (or 139081 counting only the distinct ones).

The product of its (nonzero) digits is 52254720, while the sum is 64.

Multiplying 309487491856 by its sum of digits (64), we get a square (19807199478784 = 4450528²).

The spelling of 309487491856 in words is "three hundred nine billion, four hundred eighty-seven million, four hundred ninety-one thousand, eight hundred fifty-six".