15535910661 has 4 divisors (see below), whose sum is σ = 20714547552. Its totient is φ = 10357273772.

The previous prime is 15535910657. The next prime is 15535910699. The reversal of 15535910661 is 16601953551.

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 15535910661 - 2² = 15535910657 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15535910161) 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, 2589318441 + ... + 2589318446.

It is an arithmetic number, because the mean of its divisors is an integer number (5178636888).

Almost surely, 2^15535910661 is an apocalyptic number.

It is an amenable number.

15535910661 is a deficient number, since it is larger than the sum of its proper divisors (5178636891).

15535910661 is an equidigital number, since it uses as much as digits as its factorization.

15535910661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5178636890.

The product of its (nonzero) digits is 121500, while the sum is 42.

The spelling of 15535910661 in words is "fifteen billion, five hundred thirty-five million, nine hundred ten thousand, six hundred sixty-one".