20535657 has 4 divisors (see below), whose sum is σ = 27380880. Its totient is φ = 13690436.

The previous prime is 20535653. The next prime is 20535659. The reversal of 20535657 is 75653502.

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.

It is a cyclic number.

It is not a de Polignac number, because 20535657 - 2² = 20535653 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20535653) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3422607 + ... + 3422612.

It is an arithmetic number, because the mean of its divisors is an integer number (6845220).

Almost surely, 2^20535657 is an apocalyptic number.

It is an amenable number.

20535657 is a deficient number, since it is larger than the sum of its proper divisors (6845223).

20535657 is an equidigital number, since it uses as much as digits as its factorization.

20535657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6845222.

The product of its (nonzero) digits is 31500, while the sum is 33.

The square root of 20535657 is about 4531.6285152250. The cubic root of 20535657 is about 273.8437713825.

The spelling of 20535657 in words is "twenty million, five hundred thirty-five thousand, six hundred fifty-seven".