16403013661 has 4 divisors (see below), whose sum is σ = 17116188192. Its totient is φ = 15689839132.

The previous prime is 16403013637. The next prime is 16403013667. The reversal of 16403013661 is 16631030461.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16403013661 - 2⁵ = 16403013629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16403013667) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 356587231 + ... + 356587276.

It is an arithmetic number, because the mean of its divisors is an integer number (4279047048).

Almost surely, 2^16403013661 is an apocalyptic number.

It is an amenable number.

16403013661 is a deficient number, since it is larger than the sum of its proper divisors (713174531).

16403013661 is an equidigital number, since it uses as much as digits as its factorization.

16403013661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 713174530.

The product of its (nonzero) digits is 7776, while the sum is 31.

The spelling of 16403013661 in words is "sixteen billion, four hundred three million, thirteen thousand, six hundred sixty-one".