155666516551 has 8 divisors (see below), whose sum is σ = 191589558944. Its totient is φ = 123164716320.

The previous prime is 155666516549. The next prime is 155666516573. The reversal of 155666516551 is 155615666551.

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 155666516551 - 2¹ = 155666516549 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155666516531) 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, 855310440 + ... + 855310621.

It is an arithmetic number, because the mean of its divisors is an integer number (23948694868).

Almost surely, 2^155666516551 is an apocalyptic number.

155666516551 is a deficient number, since it is larger than the sum of its proper divisors (35923042393).

155666516551 is a wasteful number, since it uses less digits than its factorization.

155666516551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1710621081.

The product of its digits is 4050000, while the sum is 52.

The spelling of 155666516551 in words is "one hundred fifty-five billion, six hundred sixty-six million, five hundred sixteen thousand, five hundred fifty-one".