20749566 has 8 divisors (see below), whose sum is σ = 41499144. Its totient is φ = 6916520.

The previous prime is 20749543. The next prime is 20749601. The reversal of 20749566 is 66594702.

It is a sphenic number, since it is the product of 3 distinct primes.

20749566 is an admirable number.

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, 1729125 + ... + 1729136.

It is an arithmetic number, because the mean of its divisors is an integer number (5187393).

Almost surely, 2^20749566 is an apocalyptic number.

20749566 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20749566 is a wasteful number, since it uses less digits than its factorization.

20749566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3458266.

The product of its (nonzero) digits is 90720, while the sum is 39.

The square root of 20749566 is about 4555.1691516342. The cubic root of 20749566 is about 274.7913171639.

The spelling of 20749566 in words is "twenty million, seven hundred forty-nine thousand, five hundred sixty-six".