16621456 has 60 divisors (see below), whose sum is σ = 35462016. Its totient is φ = 7529280.

The previous prime is 16621453. The next prime is 16621457. The reversal of 16621456 is 65412661.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16621453) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 353625 + ... + 353671.

Almost surely, 2^16621456 is an apocalyptic number.

16621456 is a gapful number since it is divisible by the number (16) 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 16621456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17731008).

16621456 is an abundant number, since it is smaller than the sum of its proper divisors (18840560).

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

16621456 is a wasteful number, since it uses less digits than its factorization.

16621456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140 (or 103 counting only the distinct ones).

The product of its digits is 8640, while the sum is 31.

The square root of 16621456 is about 4076.9419912479. The cubic root of 16621456 is about 255.2052992352.

The spelling of 16621456 in words is "sixteen million, six hundred twenty-one thousand, four hundred fifty-six".