20755559 has 4 divisors (see below), whose sum is σ = 22642440. Its totient is φ = 18868680.

The previous prime is 20755547. The next prime is 20755571. The reversal of 20755559 is 95555702.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (20755547) and next prime (20755571).

It is a cyclic number.

It is not a de Polignac number, because 20755559 - 2⁸ = 20755303 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20755519) 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, 943424 + ... + 943445.

It is an arithmetic number, because the mean of its divisors is an integer number (5660610).

Almost surely, 2^20755559 is an apocalyptic number.

20755559 is a deficient number, since it is larger than the sum of its proper divisors (1886881).

20755559 is a wasteful number, since it uses less digits than its factorization.

20755559 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1886880.

The product of its (nonzero) digits is 78750, while the sum is 38.

The square root of 20755559 is about 4555.8269282316. The cubic root of 20755559 is about 274.8177701805.

The spelling of 20755559 in words is "twenty million, seven hundred fifty-five thousand, five hundred fifty-nine".