20729888 has 12 divisors (see below), whose sum is σ = 40812030. Its totient is φ = 10364928.

The previous prime is 20729873. The next prime is 20729897. The reversal of 20729888 is 88892702.

It can be written as a sum of positive squares in only one way, i.e., 18079504 + 2650384 = 4252^2 + 1628^2 .

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323873 + ... + 323936.

Almost surely, 2^20729888 is an apocalyptic number.

It is an amenable number.

20729888 is a deficient number, since it is larger than the sum of its proper divisors (20082142).

20729888 is an equidigital number, since it uses as much as digits as its factorization.

20729888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 647819 (or 647811 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 44.

The square root of 20729888 is about 4553.0086755902. The cubic root of 20729888 is about 274.7044229158.

It can be divided in two parts, 207 and 29888, that multiplied together give a palindrome (6186816).

The spelling of 20729888 in words is "twenty million, seven hundred twenty-nine thousand, eight hundred eighty-eight".