16391390 has 16 divisors (see below), whose sum is σ = 30224880. Its totient is φ = 6396480.

The previous prime is 16391377. The next prime is 16391393. The reversal of 16391390 is 9319361.

It is a super-2 number, since 2×16391390² = 537355332264200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16391393) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19580 + ... + 20399.

It is an arithmetic number, because the mean of its divisors is an integer number (1889055).

Almost surely, 2^16391390 is an apocalyptic number.

16391390 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

16391390 is a deficient number, since it is larger than the sum of its proper divisors (13833490).

16391390 is a wasteful number, since it uses less digits than its factorization.

16391390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40027.

The product of its (nonzero) digits is 4374, while the sum is 32.

The square root of 16391390 is about 4048.6281627238. The cubic root of 16391390 is about 254.0223490782.

The spelling of 16391390 in words is "sixteen million, three hundred ninety-one thousand, three hundred ninety".