20665522 has 4 divisors (see below), whose sum is σ = 30998286. Its totient is φ = 10332760.

The previous prime is 20665501. The next prime is 20665529. The reversal of 20665522 is 22556602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 22556602 = 2 ⋅11278301.

It can be written as a sum of positive squares in only one way, i.e., 20602521 + 63001 = 4539^2 + 251^2 .

It is not an unprimeable number, because it can be changed into a prime (20665529) 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 as a sum of consecutive naturals, namely, 5166379 + ... + 5166382.

Almost surely, 2^20665522 is an apocalyptic number.

20665522 is a deficient number, since it is larger than the sum of its proper divisors (10332764).

20665522 is a wasteful number, since it uses less digits than its factorization.

20665522 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10332763.

The product of its (nonzero) digits is 7200, while the sum is 28.

The square root of 20665522 is about 4545.9346673704. The cubic root of 20665522 is about 274.4198103970.

The spelling of 20665522 in words is "twenty million, six hundred sixty-five thousand, five hundred twenty-two".