2155810666 has 8 divisors (see below), whose sum is σ = 3236892480. Its totient is φ = 1076846508.

The previous prime is 2155810663. The next prime is 2155810667. The reversal of 2155810666 is 6660185512.

2155810666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not an unprimeable number, because it can be changed into a prime (2155810663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 526866 + ... + 530941.

It is an arithmetic number, because the mean of its divisors is an integer number (404611560).

Almost surely, 2^2155810666 is an apocalyptic number.

2155810666 is a deficient number, since it is larger than the sum of its proper divisors (1081081814).

2155810666 is a wasteful number, since it uses less digits than its factorization.

2155810666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1058828.

The product of its (nonzero) digits is 86400, while the sum is 40.

The square root of 2155810666 is about 46430.7082220377. The cubic root of 2155810666 is about 1291.8245651401.

The spelling of 2155810666 in words is "two billion, one hundred fifty-five million, eight hundred ten thousand, six hundred sixty-six".