666155901 has 8 divisors (see below), whose sum is σ = 888408640. Its totient is φ = 444003552.

The previous prime is 666155873. The next prime is 666155909. The reversal of 666155901 is 109551666.

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

It is not a de Polignac number, because 666155901 - 2⁶ = 666155837 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 666155901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666155909) 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, 7936 + ... + 37353.

It is an arithmetic number, because the mean of its divisors is an integer number (111051080).

Almost surely, 2^666155901 is an apocalyptic number.

It is an amenable number.

666155901 is a deficient number, since it is larger than the sum of its proper divisors (222252739).

666155901 is a wasteful number, since it uses less digits than its factorization.

666155901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50195.

The product of its (nonzero) digits is 48600, while the sum is 39.

The square root of 666155901 is about 25809.9961449048. The cubic root of 666155901 is about 873.3573102825.

The spelling of 666155901 in words is "six hundred sixty-six million, one hundred fifty-five thousand, nine hundred one".