18491000 has 96 divisors (see below), whose sum is σ = 48381840. Its totient is φ = 6560000.

The previous prime is 18490999. The next prime is 18491003. The reversal of 18491000 is 19481.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18491003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 450980 + ... + 451020.

Almost surely, 2^18491000 is an apocalyptic number.

18491000 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 18491000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24190920).

18491000 is an abundant number, since it is smaller than the sum of its proper divisors (29890840).

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

18491000 is a wasteful number, since it uses less digits than its factorization.

18491000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114 (or 59 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 18491000 is about 4300.1162774976. The cubic root of 18491000 is about 264.4357282525.

The spelling of 18491000 in words is "eighteen million, four hundred ninety-one thousand".