155121666 has 16 divisors (see below), whose sum is σ = 354563904. Its totient is φ = 44320464.

The previous prime is 155121647. The next prime is 155121671. The reversal of 155121666 is 666121551.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1846645 + ... + 1846728.

It is an arithmetic number, because the mean of its divisors is an integer number (22160244).

Almost surely, 2^155121666 is an apocalyptic number.

155121666 is an abundant number, since it is smaller than the sum of its proper divisors (199442238).

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

155121666 is a wasteful number, since it uses less digits than its factorization.

155121666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3693385.

The product of its digits is 10800, while the sum is 33.

The square root of 155121666 is about 12454.7848636578. The cubic root of 155121666 is about 537.3090474396.

The spelling of 155121666 in words is "one hundred fifty-five million, one hundred twenty-one thousand, six hundred sixty-six".