20660428 has 6 divisors (see below), whose sum is σ = 36155756. Its totient is φ = 10330212.

The previous prime is 20660399. The next prime is 20660473. The reversal of 20660428 is 82406602.

It is a junction number, because it is equal to n+sod(n) for n = 20660396 and 20660405.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2582550 + ... + 2582557.

Almost surely, 2^20660428 is an apocalyptic number.

It is an amenable number.

20660428 is a deficient number, since it is larger than the sum of its proper divisors (15495328).

20660428 is a wasteful number, since it uses less digits than its factorization.

20660428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5165111 (or 5165109 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 20660428 is about 4545.3743520199. The cubic root of 20660428 is about 274.3972606095.

The spelling of 20660428 in words is "twenty million, six hundred sixty thousand, four hundred twenty-eight".