16621004 has 6 divisors (see below), whose sum is σ = 29086764. Its totient is φ = 8310500.

The previous prime is 16620983. The next prime is 16621013. The reversal of 16621004 is 40012661.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2077622 + ... + 2077629.

It is an arithmetic number, because the mean of its divisors is an integer number (4847794).

Almost surely, 2^16621004 is an apocalyptic number.

It is an amenable number.

16621004 is a deficient number, since it is larger than the sum of its proper divisors (12465760).

16621004 is a wasteful number, since it uses less digits than its factorization.

16621004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4155255 (or 4155253 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 16621004 is about 4076.8865571659. The cubic root of 16621004 is about 255.2029858830.

Adding to 16621004 its reverse (40012661), we get a palindrome (56633665).

The spelling of 16621004 in words is "sixteen million, six hundred twenty-one thousand, four".