20766556 has 12 divisors (see below), whose sum is σ = 36422568. Its totient is φ = 10360112.

The previous prime is 20766533. The next prime is 20766593. The reversal of 20766556 is 65566702.

It is a super-2 number, since 2×20766556² = 862499696202272, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3691 + ... + 7426.

It is an arithmetic number, because the mean of its divisors is an integer number (3035214).

Almost surely, 2^20766556 is an apocalyptic number.

It is an amenable number.

20766556 is a deficient number, since it is larger than the sum of its proper divisors (15656012).

20766556 is a wasteful number, since it uses less digits than its factorization.

20766556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11588 (or 11586 counting only the distinct ones).

The product of its (nonzero) digits is 75600, while the sum is 37.

The square root of 20766556 is about 4557.0336843170. The cubic root of 20766556 is about 274.8662975401.

The spelling of 20766556 in words is "twenty million, seven hundred sixty-six thousand, five hundred fifty-six".