15661621204141 has 4 divisors (see below), whose sum is σ = 17085404949984. Its totient is φ = 14237837458300.

The previous prime is 15661621204123. The next prime is 15661621204181. The reversal of 15661621204141 is 14140212616651.

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 15661621204141 - 2²³ = 15661612815533 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 15661621204094 and 15661621204103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15661621204181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 711891872905 + ... + 711891872926.

It is an arithmetic number, because the mean of its divisors is an integer number (4271351237496).

Almost surely, 2^{15661621204141} is an apocalyptic number.

15661621204141 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

15661621204141 is a deficient number, since it is larger than the sum of its proper divisors (1423783745843).

15661621204141 is a wasteful number, since it uses less digits than its factorization.

15661621204141 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1423783745842.

The product of its (nonzero) digits is 69120, while the sum is 40.

The spelling of 15661621204141 in words is "fifteen trillion, six hundred sixty-one billion, six hundred twenty-one million, two hundred four thousand, one hundred forty-one".