16621930 has 32 divisors (see below), whose sum is σ = 33339600. Its totient is φ = 5924352.

The previous prime is 16621897. The next prime is 16621949. The reversal of 16621930 is 3912661.

It is a Cunningham number, because it is equal to 4077²+1.

It can be written as a sum of positive squares in 8 ways, for example, as 1247689 + 15374241 = 1117^2 + 3921^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1566 + ... + 5974.

Almost surely, 2^16621930 is an apocalyptic number.

16621930 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

16621930 is an abundant number, since it is smaller than the sum of its proper divisors (16717670).

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

16621930 is a wasteful number, since it uses less digits than its factorization.

16621930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4458.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 16621930 is about 4077.0001226392. Note that the first 3 decimals coincide. The cubic root of 16621930 is about 255.2077251390.

The spelling of 16621930 in words is "sixteen million, six hundred twenty-one thousand, nine hundred thirty".