20642711 has 4 divisors (see below), whose sum is σ = 20667024. Its totient is φ = 20618400.

The previous prime is 20642689. The next prime is 20642731. The reversal of 20642711 is 11724602.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20642711 - 2⁶ = 20642647 is a prime.

It is a super-2 number, since 2×20642711² = 852243034859042, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20642731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10835 + ... + 12596.

It is an arithmetic number, because the mean of its divisors is an integer number (5166756).

Almost surely, 2^20642711 is an apocalyptic number.

20642711 is a deficient number, since it is larger than the sum of its proper divisors (24313).

20642711 is an equidigital number, since it uses as much as digits as its factorization.

20642711 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24312.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 20642711 is about 4543.4250296445. The cubic root of 20642711 is about 274.3188032713.

The spelling of 20642711 in words is "twenty million, six hundred forty-two thousand, seven hundred eleven".