18191016 has 48 divisors (see below), whose sum is σ = 49956660. Its totient is φ = 5978880.

The previous prime is 18190979. The next prime is 18191023. The reversal of 18191016 is 61019181.

It can be written as a sum of positive squares in 2 ways, for example, as 17892900 + 298116 = 4230^2 + 546^2 .

It is a super-2 number, since 2×18191016² = 661826126224512, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3526 + ... + 6986.

Almost surely, 2^18191016 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18191016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24978330).

18191016 is an abundant number, since it is smaller than the sum of its proper divisors (31765644).

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

18191016 is a wasteful number, since it uses less digits than its factorization.

18191016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3546 (or 3539 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 27.

The square root of 18191016 is about 4265.0927305277. The cubic root of 18191016 is about 262.9979229452.

The spelling of 18191016 in words is "eighteen million, one hundred ninety-one thousand, sixteen".