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20990369 = 712291291
BaseRepresentation
bin101000000010…
…0100110100001
31110111102101002
41100010212201
520333142434
62025521345
7343262261
oct120044641
943442332
1020990369
1110937414
127043255
13446c14a
142b057a1
151c9957e
hex14049a1

20990369 has 8 divisors (see below), whose sum is σ = 21395520. Its totient is φ = 20588400.

The previous prime is 20990353. The next prime is 20990399. The reversal of 20990369 is 96309902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20990369 - 24 = 20990353 is a prime.

It is a super-2 number, since 2×209903692 = 881191181512322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20990399) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15614 + ... + 16904.

It is an arithmetic number, because the mean of its divisors is an integer number (2674440).

Almost surely, 220990369 is an apocalyptic number.

It is an amenable number.

20990369 is a deficient number, since it is larger than the sum of its proper divisors (405151).

20990369 is a wasteful number, since it uses less digits than its factorization.

20990369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1591.

The product of its (nonzero) digits is 26244, while the sum is 38.

The square root of 20990369 is about 4581.5247461953. The cubic root of 20990369 is about 275.8502346829.

The spelling of 20990369 in words is "twenty million, nine hundred ninety thousand, three hundred sixty-nine".

Divisors: 1 71 229 1291 16259 91661 295639 20990369