16400320 has 56 divisors (see below), whose sum is σ = 39831264. Its totient is φ = 6429696.

The previous prime is 16400317. The next prime is 16400347. The reversal of 16400320 is 2300461.

It is a super-2 number, since 2×16400320² = 537940992204800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a junction number, because it is equal to n+sod(n) for n = 16400294 and 16400303.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16477 + ... + 17443.

Almost surely, 2^16400320 is an apocalyptic number.

16400320 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 16400320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19915632).

16400320 is an abundant number, since it is smaller than the sum of its proper divisors (23430944).

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

16400320 is an equidigital number, since it uses as much as digits as its factorization.

16400320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1037 (or 1027 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 16400320 is about 4049.7308552545. The cubic root of 16400320 is about 254.0684710109.

Adding to 16400320 its reverse (2300461), we get a palindrome (18700781).

The spelling of 16400320 in words is "sixteen million, four hundred thousand, three hundred twenty".