15781379509 has 8 divisors (see below), whose sum is σ = 18114623360. Its totient is φ = 13467825936.

The previous prime is 15781379507. The next prime is 15781379543. The reversal of 15781379509 is 90597318751.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 15781379509 - 2¹ = 15781379507 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 15781379509.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15781379501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4920849 + ... + 4924054.

It is an arithmetic number, because the mean of its divisors is an integer number (2264327920).

Almost surely, 2^15781379509 is an apocalyptic number.

It is an amenable number.

15781379509 is a deficient number, since it is larger than the sum of its proper divisors (2333243851).

15781379509 is an equidigital number, since it uses as much as digits as its factorization.

15781379509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9845139.

The product of its (nonzero) digits is 2381400, while the sum is 55.

The spelling of 15781379509 in words is "fifteen billion, seven hundred eighty-one million, three hundred seventy-nine thousand, five hundred nine".