20289551 has 4 divisors (see below), whose sum is σ = 21483072. Its totient is φ = 19096032.

The previous prime is 20289541. The next prime is 20289553. The reversal of 20289551 is 15598202.

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

It is a de Polignac number, because none of the positive numbers 2^k-20289551 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 (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, 596735 + ... + 596768.

It is an arithmetic number, because the mean of its divisors is an integer number (5370768).

Almost surely, 2^20289551 is an apocalyptic number.

20289551 is a deficient number, since it is larger than the sum of its proper divisors (1193521).

20289551 is a wasteful number, since it uses less digits than its factorization.

20289551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1193520.

The product of its (nonzero) digits is 7200, while the sum is 32.

The square root of 20289551 is about 4504.3924118576. The cubic root of 20289551 is about 272.7454276837.

The spelling of 20289551 in words is "twenty million, two hundred eighty-nine thousand, five hundred fifty-one".