15666156655542 has 48 divisors (see below), whose sum is σ = 35753169741120. Its totient is φ = 4943975842800.

The previous prime is 15666156655507. The next prime is 15666156655553. The reversal of 15666156655542 is 24555665166651.

It is a self number, because there is not a number n which added to its sum of digits gives 15666156655542.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14436384 + ... + 15483587.

It is an arithmetic number, because the mean of its divisors is an integer number (744857702940).

Almost surely, 2^{15666156655542} is an apocalyptic number.

15666156655542 is an abundant number, since it is smaller than the sum of its proper divisors (20087013085578).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

15666156655542 is a wasteful number, since it uses less digits than its factorization.

15666156655542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29921529 (or 29921526 counting only the distinct ones).

The product of its digits is 194400000, while the sum is 63.

The spelling of 15666156655542 in words is "fifteen trillion, six hundred sixty-six billion, one hundred fifty-six million, six hundred fifty-five thousand, five hundred forty-two".