20649533 has 4 divisors (see below), whose sum is σ = 20684160. Its totient is φ = 20614908.

The previous prime is 20649529. The next prime is 20649539. The reversal of 20649533 is 33594602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 33594602 = 2 ⋅16797301.

It is a cyclic number.

It is not a de Polignac number, because 20649533 - 2² = 20649529 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20649533.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20649539) 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, 16403 + ... + 17616.

It is an arithmetic number, because the mean of its divisors is an integer number (5171040).

Almost surely, 2^20649533 is an apocalyptic number.

It is an amenable number.

20649533 is a deficient number, since it is larger than the sum of its proper divisors (34627).

20649533 is an equidigital number, since it uses as much as digits as its factorization.

20649533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34626.

The product of its (nonzero) digits is 19440, while the sum is 32.

The square root of 20649533 is about 4544.1757228347. The cubic root of 20649533 is about 274.3490188885.

The spelling of 20649533 in words is "twenty million, six hundred forty-nine thousand, five hundred thirty-three".