20742065 has 4 divisors (see below), whose sum is σ = 24890484. Its totient is φ = 16593648.

The previous prime is 20742041. The next prime is 20742077. The reversal of 20742065 is 56024702.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56024702 = 2 ⋅28012351.

It can be written as a sum of positive squares in 2 ways, for example, as 10863616 + 9878449 = 3296^2 + 3143^2 .

It is a cyclic number.

It is not a de Polignac number, because 20742065 - 2¹⁰ = 20741041 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2074202 + ... + 2074211.

It is an arithmetic number, because the mean of its divisors is an integer number (6222621).

Almost surely, 2^20742065 is an apocalyptic number.

It is an amenable number.

20742065 is a deficient number, since it is larger than the sum of its proper divisors (4148419).

20742065 is an equidigital number, since it uses as much as digits as its factorization.

20742065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4148418.

The product of its (nonzero) digits is 3360, while the sum is 26.

The square root of 20742065 is about 4554.3457268855. The cubic root of 20742065 is about 274.7582006785.

Adding to 20742065 its reverse (56024702), we get a palindrome (76766767).

The spelling of 20742065 in words is "twenty million, seven hundred forty-two thousand, sixty-five".