16661650 has 12 divisors (see below), whose sum is σ = 30990762. Its totient is φ = 6664640.

The previous prime is 16661629. The next prime is 16661681. The reversal of 16661650 is 5616661.

It can be written as a sum of positive squares in 3 ways, for example, as 15000129 + 1661521 = 3873^2 + 1289^2 .

It is a super-2 number, since 2×16661650² = 555221161445000, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 166567 + ... + 166666.

Almost surely, 2^16661650 is an apocalyptic number.

16661650 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

16661650 is a deficient number, since it is larger than the sum of its proper divisors (14329112).

16661650 is a wasteful number, since it uses less digits than its factorization.

16661650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333245 (or 333240 counting only the distinct ones).

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

The square root of 16661650 is about 4081.8684447199. The cubic root of 16661650 is about 255.4108460994.

It can be divided in two parts, 166 and 61650, that added together give a palindrome (61816).

The spelling of 16661650 in words is "sixteen million, six hundred sixty-one thousand, six hundred fifty".