20708429 has 6 divisors (see below), whose sum is σ = 24089454. Its totient is φ = 17750040.

The previous prime is 20708399. The next prime is 20708447. The reversal of 20708429 is 92480702.

It can be written as a sum of positive squares in only one way, i.e., 20702500 + 5929 = 4550^2 + 77^2 .

It is a de Polignac number, because none of the positive numbers 2^k-20708429 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20708395 and 20708404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20708489) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 211262 + ... + 211359.

It is an arithmetic number, because the mean of its divisors is an integer number (4014909).

Almost surely, 2^20708429 is an apocalyptic number.

It is an amenable number.

20708429 is a deficient number, since it is larger than the sum of its proper divisors (3381025).

20708429 is an equidigital number, since it uses as much as digits as its factorization.

20708429 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 422635 (or 422628 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 20708429 is about 4550.6514918196. The cubic root of 20708429 is about 274.6096014121.

The spelling of 20708429 in words is "twenty million, seven hundred eight thousand, four hundred twenty-nine".