16661425 has 24 divisors (see below), whose sum is σ = 23078880. Its totient is φ = 11827200.

The previous prime is 16661419. The next prime is 16661429. The reversal of 16661425 is 52416661.

16661425 = T₁₇₃₅ + T₁₇₃₆ + ... + T₁₇₄₅.

It is not a de Polignac number, because 16661425 - 2³ = 16661417 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16661429) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11121 + ... + 12529.

It is an arithmetic number, because the mean of its divisors is an integer number (961620).

Almost surely, 2^16661425 is an apocalyptic number.

It is an amenable number.

16661425 is a deficient number, since it is larger than the sum of its proper divisors (6417455).

16661425 is a wasteful number, since it uses less digits than its factorization.

16661425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1473 (or 1468 counting only the distinct ones).

The product of its digits is 8640, while the sum is 31.

The square root of 16661425 is about 4081.8408837190. The cubic root of 16661425 is about 255.4096963994.

The spelling of 16661425 in words is "sixteen million, six hundred sixty-one thousand, four hundred twenty-five".