18991350 has 72 divisors (see below), whose sum is σ = 58322160. Its totient is φ = 4340160.

The previous prime is 18991319. The next prime is 18991361. The reversal of 18991350 is 5319981.

It is a happy number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 136 + ... + 6164.

It is an arithmetic number, because the mean of its divisors is an integer number (810030).

Almost surely, 2^18991350 is an apocalyptic number.

18991350 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18991350, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29161080).

18991350 is an abundant number, since it is smaller than the sum of its proper divisors (39330810).

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

18991350 is a wasteful number, since it uses less digits than its factorization.

18991350 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6054 (or 6046 counting only the distinct ones).

The product of its (nonzero) digits is 9720, while the sum is 36.

The square root of 18991350 is about 4357.9066075353. The cubic root of 18991350 is about 266.7996645601.

It can be divided in two parts, 1899 and 1350, that added together give a square (3249 = 57²).

The spelling of 18991350 in words is "eighteen million, nine hundred ninety-one thousand, three hundred fifty".