15505004661 has 4 divisors (see below), whose sum is σ = 20673339552. Its totient is φ = 10336669772.

The previous prime is 15505004659. The next prime is 15505004693. The reversal of 15505004661 is 16640050551.

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 15505004661 - 2¹ = 15505004659 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15505004611) 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, 2584167441 + ... + 2584167446.

It is an arithmetic number, because the mean of its divisors is an integer number (5168334888).

Almost surely, 2^15505004661 is an apocalyptic number.

It is an amenable number.

15505004661 is a deficient number, since it is larger than the sum of its proper divisors (5168334891).

15505004661 is an equidigital number, since it uses as much as digits as its factorization.

15505004661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5168334890.

The product of its (nonzero) digits is 18000, while the sum is 33.

The spelling of 15505004661 in words is "fifteen billion, five hundred five million, four thousand, six hundred sixty-one".