16721125 has 8 divisors (see below), whose sum is σ = 20868120. Its totient is φ = 13376800.

The previous prime is 16721119. The next prime is 16721141. The reversal of 16721125 is 52112761.

It can be written as a sum of positive squares in 4 ways, for example, as 66564 + 16654561 = 258^2 + 4081^2 .

It is not a de Polignac number, because 16721125 - 2⁵ = 16721093 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a self number, because there is not a number n which added to its sum of digits gives 16721125.

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, 66760 + ... + 67009.

It is an arithmetic number, because the mean of its divisors is an integer number (2608515).

Almost surely, 2^16721125 is an apocalyptic number.

It is an amenable number.

16721125 is a deficient number, since it is larger than the sum of its proper divisors (4146995).

16721125 is an equidigital number, since it uses as much as digits as its factorization.

16721125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133784 (or 133774 counting only the distinct ones).

The product of its digits is 840, while the sum is 25.

The square root of 16721125 is about 4089.1472216099. The cubic root of 16721125 is about 255.7143878899.

Adding to 16721125 its reverse (52112761), we get a palindrome (68833886).

The spelling of 16721125 in words is "sixteen million, seven hundred twenty-one thousand, one hundred twenty-five".