18162661 has 4 divisors (see below), whose sum is σ = 19813824. Its totient is φ = 16511500.

The previous prime is 18162637. The next prime is 18162667. The reversal of 18162661 is 16626181.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18162661 - 2⁷ = 18162533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18162667) 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, 825565 + ... + 825586.

It is an arithmetic number, because the mean of its divisors is an integer number (4953456).

Almost surely, 2^18162661 is an apocalyptic number.

18162661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18162661 is a deficient number, since it is larger than the sum of its proper divisors (1651163).

18162661 is a wasteful number, since it uses less digits than its factorization.

18162661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1651162.

The product of its digits is 3456, while the sum is 31.

The square root of 18162661 is about 4261.7673563910. The cubic root of 18162661 is about 262.8612037332.

The spelling of 18162661 in words is "eighteen million, one hundred sixty-two thousand, six hundred sixty-one".