18161619 has 16 divisors (see below), whose sum is σ = 27740160. Its totient is φ = 10353600.

The previous prime is 18161581. The next prime is 18161621. The reversal of 18161619 is 91616181.

It is not a de Polignac number, because 18161619 - 2¹¹ = 18159571 is a prime.

It is a super-2 number, since 2×18161619² = 659688809402322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 18161619.

It is not an unprimeable number, because it can be changed into a prime (18161659) 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, 11902 + ... + 13340.

It is an arithmetic number, because the mean of its divisors is an integer number (1733760).

Almost surely, 2^18161619 is an apocalyptic number.

18161619 is a deficient number, since it is larger than the sum of its proper divisors (9578541).

18161619 is a wasteful number, since it uses less digits than its factorization.

18161619 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2050.

The product of its digits is 2592, while the sum is 33.

The square root of 18161619 is about 4261.6451048861. The cubic root of 18161619 is about 262.8561768154.

The spelling of 18161619 in words is "eighteen million, one hundred sixty-one thousand, six hundred nineteen".