20729908 has 6 divisors (see below), whose sum is σ = 36277346. Its totient is φ = 10364952.

The previous prime is 20729903. The next prime is 20729909. The reversal of 20729908 is 80992702.

It can be written as a sum of positive squares in only one way, i.e., 13823524 + 6906384 = 3718^2 + 2628^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20729903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2591235 + ... + 2591242.

Almost surely, 2^20729908 is an apocalyptic number.

It is an amenable number.

20729908 is a deficient number, since it is larger than the sum of its proper divisors (15547438).

20729908 is a wasteful number, since it uses less digits than its factorization.

20729908 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5182481 (or 5182479 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 37.

The square root of 20729908 is about 4553.0108719396. The cubic root of 20729908 is about 274.7045112599.

The spelling of 20729908 in words is "twenty million, seven hundred twenty-nine thousand, nine hundred eight".