20729966 has 16 divisors (see below), whose sum is σ = 31636656. Its totient is φ = 10186176.

The previous prime is 20729939. The next prime is 20729981. The reversal of 20729966 is 66992702.

It is a happy number.

It is a super-2 number, since 2×20729966² = 859462980722312, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33290 + ... + 33906.

It is an arithmetic number, because the mean of its divisors is an integer number (1977291).

Almost surely, 2^20729966 is an apocalyptic number.

20729966 is a deficient number, since it is larger than the sum of its proper divisors (10906690).

20729966 is a wasteful number, since it uses less digits than its factorization.

20729966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 883.

The product of its (nonzero) digits is 81648, while the sum is 41.

The square root of 20729966 is about 4553.0172413467. The cubic root of 20729966 is about 274.7047674573.

The spelling of 20729966 in words is "twenty million, seven hundred twenty-nine thousand, nine hundred sixty-six".