20533639 has 8 divisors (see below), whose sum is σ = 23709728. Its totient is φ = 17418240.

The previous prime is 20533633. The next prime is 20533649. The reversal of 20533639 is 93633502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20533639 - 2⁵ = 20533607 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20533639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20533633) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14442 + ... + 15799.

It is an arithmetic number, because the mean of its divisors is an integer number (2963716).

Almost surely, 2^20533639 is an apocalyptic number.

20533639 is a deficient number, since it is larger than the sum of its proper divisors (3176089).

20533639 is an equidigital number, since it uses as much as digits as its factorization.

20533639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30345.

The product of its (nonzero) digits is 14580, while the sum is 31.

The square root of 20533639 is about 4531.4058524921. The cubic root of 20533639 is about 273.8348010530.

The spelling of 20533639 in words is "twenty million, five hundred thirty-three thousand, six hundred thirty-nine".