20859247 has 4 divisors (see below), whose sum is σ = 20967520. Its totient is φ = 20750976.

The previous prime is 20859233. The next prime is 20859253. The reversal of 20859247 is 74295802.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20859247 is a prime.

It is a super-3 number, since 3×20859247³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20859547) 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, 53847 + ... + 54232.

It is an arithmetic number, because the mean of its divisors is an integer number (5241880).

Almost surely, 2^20859247 is an apocalyptic number.

20859247 is a deficient number, since it is larger than the sum of its proper divisors (108273).

20859247 is a wasteful number, since it uses less digits than its factorization.

20859247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108272.

The product of its (nonzero) digits is 40320, while the sum is 37.

The square root of 20859247 is about 4567.1924636477. The cubic root of 20859247 is about 275.2746435275.

The spelling of 20859247 in words is "twenty million, eight hundred fifty-nine thousand, two hundred forty-seven".