15661658441 has 8 divisors (see below), whose sum is σ = 18399710784. Its totient is φ = 13142650320.

The previous prime is 15661658437. The next prime is 15661658443. The reversal of 15661658441 is 14485616651.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 15661658441 - 2² = 15661658437 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (15661658443) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 54760901 + ... + 54761186.

It is an arithmetic number, because the mean of its divisors is an integer number (2299963848).

Almost surely, 2^15661658441 is an apocalyptic number.

15661658441 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

15661658441 is a deficient number, since it is larger than the sum of its proper divisors (2738052343).

15661658441 is a wasteful number, since it uses less digits than its factorization.

15661658441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109522111.

The product of its digits is 691200, while the sum is 47.

The spelling of 15661658441 in words is "fifteen billion, six hundred sixty-one million, six hundred fifty-eight thousand, four hundred forty-one".