20851343 has 4 divisors (see below), whose sum is σ = 21102648. Its totient is φ = 20600040.

The previous prime is 20851331. The next prime is 20851361. The reversal of 20851343 is 34315802.

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

It is a cyclic number.

It is not a de Polignac number, because 20851343 - 2¹² = 20847247 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 (20851643) 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, 125528 + ... + 125693.

It is an arithmetic number, because the mean of its divisors is an integer number (5275662).

Almost surely, 2^20851343 is an apocalyptic number.

20851343 is a deficient number, since it is larger than the sum of its proper divisors (251305).

20851343 is an equidigital number, since it uses as much as digits as its factorization.

20851343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251304.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 20851343 is about 4566.3270798312. The cubic root of 20851343 is about 275.2398700502.

The spelling of 20851343 in words is "twenty million, eight hundred fifty-one thousand, three hundred forty-three".