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20877289 = 199104911
BaseRepresentation
bin100111110100…
…0111111101001
31110021200020221
41033220333221
520321033124
62023250041
7342311506
oct117507751
943250227
1020877289
111086a464
126ba9921
13442c834
142ab64ad
151c75ce4
hex13e8fe9

20877289 has 4 divisors (see below), whose sum is σ = 20982400. Its totient is φ = 20772180.

The previous prime is 20877281. The next prime is 20877299. The reversal of 20877289 is 98277802.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20877289 - 23 = 20877281 is a prime.

It is a super-2 number, since 2×208772892 = 871722391979042, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20877281) 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, 52257 + ... + 52654.

It is an arithmetic number, because the mean of its divisors is an integer number (5245600).

Almost surely, 220877289 is an apocalyptic number.

It is an amenable number.

20877289 is a deficient number, since it is larger than the sum of its proper divisors (105111).

20877289 is a wasteful number, since it uses less digits than its factorization.

20877289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105110.

The product of its (nonzero) digits is 112896, while the sum is 43.

The square root of 20877289 is about 4569.1672107727. The cubic root of 20877289 is about 275.3539860192.

The spelling of 20877289 in words is "twenty million, eight hundred seventy-seven thousand, two hundred eighty-nine".

Divisors: 1 199 104911 20877289