15661646023 has 4 divisors (see below), whose sum is σ = 15662220480. Its totient is φ = 15661071568.

The previous prime is 15661646009. The next prime is 15661646029. The reversal of 15661646023 is 32064616651.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32064616651 = 53 ⋅604992767.

It is a cyclic number.

It is not a de Polignac number, because 15661646023 - 2³³ = 7071711431 is a prime.

It is a super-2 number, since 2×15661646023² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15661646029) 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, 244183 + ... + 301576.

It is an arithmetic number, because the mean of its divisors is an integer number (3915555120).

Almost surely, 2^15661646023 is an apocalyptic number.

15661646023 is a deficient number, since it is larger than the sum of its proper divisors (574457).

15661646023 is an equidigital number, since it uses as much as digits as its factorization.

15661646023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 574456.

The product of its (nonzero) digits is 155520, while the sum is 40.

The spelling of 15661646023 in words is "fifteen billion, six hundred sixty-one million, six hundred forty-six thousand, twenty-three".