20522657 has 4 divisors (see below), whose sum is σ = 20859156. Its totient is φ = 20186160.

The previous prime is 20522639. The next prime is 20522659. The reversal of 20522657 is 75622502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75622502 = 2 ⋅37811251.

It can be written as a sum of positive squares in 2 ways, for example, as 844561 + 19678096 = 919^2 + 4436^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20522657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20522659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 168158 + ... + 168279.

It is an arithmetic number, because the mean of its divisors is an integer number (5214789).

Almost surely, 2^20522657 is an apocalyptic number.

It is an amenable number.

20522657 is a deficient number, since it is larger than the sum of its proper divisors (336499).

20522657 is an equidigital number, since it uses as much as digits as its factorization.

20522657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 336498.

The product of its (nonzero) digits is 8400, while the sum is 29.

The square root of 20522657 is about 4530.1939252089. The cubic root of 20522657 is about 273.7859740190.

The spelling of 20522657 in words is "twenty million, five hundred twenty-two thousand, six hundred fifty-seven".