15309985509 has 144 divisors (see below), whose sum is σ = 29351038080. Its totient is φ = 7465893120.

The previous prime is 15309985487. The next prime is 15309985519. The reversal of 15309985509 is 90558990351.

It is a happy number.

15309985509 is a `hidden beast` number, since 1 + 53 + 0 + 9 + 9 + 85 + 509 = 666.

It is not a de Polignac number, because 15309985509 - 2⁹ = 15309984997 is a prime.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15309985519) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 120551004 + ... + 120551130.

Almost surely, 2^15309985509 is an apocalyptic number.

15309985509 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

15309985509 is a deficient number, since it is larger than the sum of its proper divisors (14041052571).

15309985509 is a wasteful number, since it uses less digits than its factorization.

15309985509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 360 (or 230 counting only the distinct ones).

The product of its (nonzero) digits is 2187000, while the sum is 54.

The spelling of 15309985509 in words is "fifteen billion, three hundred nine million, nine hundred eighty-five thousand, five hundred nine".