20289556 has 12 divisors (see below), whose sum is σ = 40579168. Its totient is φ = 8695512.

The previous prime is 20289553. The next prime is 20289559. The reversal of 20289556 is 65598202.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20289553) and next prime (20289559).

20289556 is an admirable number.

It is a super-3 number, since 3×20289556³ (a number of 23 digits) contains 333 as substring.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20289553) 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, 362286 + ... + 362341.

Almost surely, 2^20289556 is an apocalyptic number.

It is an amenable number.

20289556 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20289556 is a wasteful number, since it uses less digits than its factorization.

20289556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 724638 (or 724636 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 37.

The square root of 20289556 is about 4504.3929668713. The cubic root of 20289556 is about 272.7454500881.

The spelling of 20289556 in words is "twenty million, two hundred eighty-nine thousand, five hundred fifty-six".