16690225 has 12 divisors (see below), whose sum is σ = 21410460. Its totient is φ = 12891200.

The previous prime is 16690211. The next prime is 16690229. The reversal of 16690225 is 52209661.

It can be written as a sum of positive squares in 6 ways, for example, as 1852321 + 14837904 = 1361^2 + 3852^2 .

It is not a de Polignac number, because 16690225 - 2⁹ = 16689713 is a prime.

It is a super-2 number, since 2×16690225² = 557127221101250, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (16690229) 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, 10786 + ... + 12235.

It is an arithmetic number, because the mean of its divisors is an integer number (1784205).

Almost surely, 2^16690225 is an apocalyptic number.

It is an amenable number.

16690225 is a deficient number, since it is larger than the sum of its proper divisors (4720235).

16690225 is a wasteful number, since it uses less digits than its factorization.

16690225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23060 (or 23055 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 16690225 is about 4085.3671805604. The cubic root of 16690225 is about 255.5567739562.

Adding to 16690225 its reverse (52209661), we get a palindrome (68899886).

The spelling of 16690225 in words is "sixteen million, six hundred ninety thousand, two hundred twenty-five".