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BaseRepresentation
bin101000110011…
…0011000000101
31111020202201211
41101212120011
520434001403
62042251421
7346551001
oct121463005
944222654
1021390853
11110902a0
1271b6b71
13457c513
142bab701
151d2806d
hex1466605

21390853 has 8 divisors (see below), whose sum is σ = 23776416. Its totient is φ = 19078800.

The previous prime is 21390833. The next prime is 21390857. The reversal of 21390853 is 35809312.

It is a happy number.

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 21390853 - 213 = 21382661 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 (21390857) 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, 17763 + ... + 18928.

It is an arithmetic number, because the mean of its divisors is an integer number (2972052).

Almost surely, 221390853 is an apocalyptic number.

It is an amenable number.

21390853 is a deficient number, since it is larger than the sum of its proper divisors (2385563).

21390853 is a wasteful number, since it uses less digits than its factorization.

21390853 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36755.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 21390853 is about 4625.0246485830. The cubic root of 21390853 is about 277.5935479860.

The spelling of 21390853 in words is "twenty-one million, three hundred ninety thousand, eight hundred fifty-three".

Divisors: 1 11 53 583 36691 403601 1944623 21390853