16661644 has 6 divisors (see below), whose sum is σ = 29157884. Its totient is φ = 8330820.

The previous prime is 16661629. The next prime is 16661681. The reversal of 16661644 is 44616661.

It is a super-2 number, since 2×16661644² = 555220761565472, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2082702 + ... + 2082709.

Almost surely, 2^16661644 is an apocalyptic number.

It is an amenable number.

16661644 is a deficient number, since it is larger than the sum of its proper divisors (12496240).

16661644 is a wasteful number, since it uses less digits than its factorization.

16661644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4165415 (or 4165413 counting only the distinct ones).

The product of its digits is 20736, while the sum is 34.

The square root of 16661644 is about 4081.8677097623. The cubic root of 16661644 is about 255.4108154409.

The spelling of 16661644 in words is "sixteen million, six hundred sixty-one thousand, six hundred forty-four".