15685040405 has 6 divisors (see below), whose sum is σ = 18822384546. Its totient is φ = 12547808288.

The previous prime is 15685040389. The next prime is 15685040419. The reversal of 15685040405 is 50404058651.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 9162701284 + 6522339121 = 95722^2 + 80761^2 .

It is not a de Polignac number, because 15685040405 - 2⁴ = 15685040389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 252041 + ... + 308049.

It is an arithmetic number, because the mean of its divisors is an integer number (3137064091).

Almost surely, 2^15685040405 is an apocalyptic number.

It is an amenable number.

15685040405 is a deficient number, since it is larger than the sum of its proper divisors (3137344141).

15685040405 is an frugal number, since it uses more digits than its factorization.

15685040405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112023 (or 56014 counting only the distinct ones).

The product of its (nonzero) digits is 96000, while the sum is 38.

The spelling of 15685040405 in words is "fifteen billion, six hundred eighty-five million, forty thousand, four hundred five".