18101661 has 16 divisors (see below), whose sum is σ = 25536000. Its totient is φ = 11374128.

The previous prime is 18101659. The next prime is 18101669. The reversal of 18101661 is 16610181.

It is not a de Polignac number, because 18101661 - 2¹ = 18101659 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18101669) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12240 + ... + 13638.

It is an arithmetic number, because the mean of its divisors is an integer number (1596000).

Almost surely, 2^18101661 is an apocalyptic number.

It is an amenable number.

18101661 is a deficient number, since it is larger than the sum of its proper divisors (7434339).

18101661 is a wasteful number, since it uses less digits than its factorization.

18101661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1648.

The product of its (nonzero) digits is 288, while the sum is 24.

The square root of 18101661 is about 4254.6046819887. The cubic root of 18101661 is about 262.5665971616.

The spelling of 18101661 in words is "eighteen million, one hundred one thousand, six hundred sixty-one".