16620818 has 4 divisors (see below), whose sum is σ = 24931230. Its totient is φ = 8310408.

The previous prime is 16620787. The next prime is 16620827. The reversal of 16620818 is 81802661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81802661 = 953 ⋅85837.

It can be written as a sum of positive squares in only one way, i.e., 15976009 + 644809 = 3997^2 + 803^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4155203 + ... + 4155206.

Almost surely, 2^16620818 is an apocalyptic number.

16620818 is a deficient number, since it is larger than the sum of its proper divisors (8310412).

16620818 is an equidigital number, since it uses as much as digits as its factorization.

16620818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8310411.

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 16620818 is about 4076.8637455770. The cubic root of 16620818 is about 255.2020339162.

The spelling of 16620818 in words is "sixteen million, six hundred twenty thousand, eight hundred eighteen".