18361920 has 112 divisors (see below), whose sum is σ = 60277248. Its totient is φ = 4730880.

The previous prime is 18361897. The next prime is 18361957. The reversal of 18361920 is 2916381.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29452 + ... + 30068.

Almost surely, 2^18361920 is an apocalyptic number.

18361920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18361920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30138624).

18361920 is an abundant number, since it is smaller than the sum of its proper divisors (41915328).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18361920 is a wasteful number, since it uses less digits than its factorization.

18361920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 668 (or 658 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 18361920 is about 4285.0810960821. The cubic root of 18361920 is about 263.8189759926.

The spelling of 18361920 in words is "eighteen million, three hundred sixty-one thousand, nine hundred twenty".