16191090 has 56 divisors (see below), whose sum is σ = 43715628. Its totient is φ = 4315680.

The previous prime is 16191079. The next prime is 16191101. The reversal of 16191090 is 9019161.

It is an interprime number because it is at equal distance from previous prime (16191079) and next prime (16191101).

It can be written as a sum of positive squares in 2 ways, for example, as 16184529 + 6561 = 4023^2 + 81^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 6180 + ... + 8400.

Almost surely, 2^16191090 is an apocalyptic number.

16191090 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 16191090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21857814).

16191090 is an abundant number, since it is smaller than the sum of its proper divisors (27524538).

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

16191090 is an equidigital number, since it uses as much as digits as its factorization.

16191090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2246 (or 2231 counting only the distinct ones).

The product of its (nonzero) digits is 486, while the sum is 27.

The square root of 16191090 is about 4023.8153536165. The cubic root of 16191090 is about 252.9834022867.

The spelling of 16191090 in words is "sixteen million, one hundred ninety-one thousand, ninety".