20495729 has 4 divisors (see below), whose sum is σ = 20585460. Its totient is φ = 20406000.

The previous prime is 20495719. The next prime is 20495731. The reversal of 20495729 is 92759402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 92759402 = 2 ⋅46379701.

It can be written as a sum of positive squares in 2 ways, for example, as 19936225 + 559504 = 4465^2 + 748^2 .

It is a cyclic number.

It is not a de Polignac number, because 20495729 - 2⁸ = 20495473 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20495692 and 20495701.

It is not an unprimeable number, because it can be changed into a prime (20495719) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44522 + ... + 44979.

It is an arithmetic number, because the mean of its divisors is an integer number (5146365).

Almost surely, 2^20495729 is an apocalyptic number.

It is an amenable number.

20495729 is a deficient number, since it is larger than the sum of its proper divisors (89731).

20495729 is an equidigital number, since it uses as much as digits as its factorization.

20495729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89730.

The product of its (nonzero) digits is 45360, while the sum is 38.

The square root of 20495729 is about 4527.2208914521. The cubic root of 20495729 is about 273.6661757626. Note that the first 3 decimals are identical.

The spelling of 20495729 in words is "twenty million, four hundred ninety-five thousand, seven hundred twenty-nine".