20429857 has 12 divisors (see below), whose sum is σ = 23820160. Its totient is φ = 17164368.

The previous prime is 20429821. The next prime is 20429863. The reversal of 20429857 is 75892402.

It is a de Polignac number, because none of the positive numbers 2^k-20429857 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20429557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19144 + ... + 20182.

Almost surely, 2^20429857 is an apocalyptic number.

It is an amenable number.

20429857 is a deficient number, since it is larger than the sum of its proper divisors (3390303).

20429857 is an equidigital number, since it uses as much as digits as its factorization.

20429857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1152 (or 1099 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 37.

The square root of 20429857 is about 4519.9399332292. The cubic root of 20429857 is about 273.3726790805.

The spelling of 20429857 in words is "twenty million, four hundred twenty-nine thousand, eight hundred fifty-seven".