15661504003 has 4 divisors (see below), whose sum is σ = 15661853928. Its totient is φ = 15661154080.

The previous prime is 15661503953. The next prime is 15661504009. The reversal of 15661504003 is 30040516651.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 15661504003 - 2¹⁷ = 15661372931 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15661504009) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 95926 + ... + 201307.

It is an arithmetic number, because the mean of its divisors is an integer number (3915463482).

Almost surely, 2^15661504003 is an apocalyptic number.

15661504003 is a deficient number, since it is larger than the sum of its proper divisors (349925).

15661504003 is an equidigital number, since it uses as much as digits as its factorization.

15661504003 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 349924.

The product of its (nonzero) digits is 10800, while the sum is 31.

The spelling of 15661504003 in words is "fifteen billion, six hundred sixty-one million, five hundred four thousand, three".