20859973 has 4 divisors (see below), whose sum is σ = 20874220. Its totient is φ = 20845728.

The previous prime is 20859953. The next prime is 20859977. The reversal of 20859973 is 37995802.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 3869089 + 16990884 = 1967^2 + 4122^2 .

It is a cyclic number.

It is not a de Polignac number, because 20859973 - 2¹³ = 20851781 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 (20859977) 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, 4638 + ... + 7951.

It is an arithmetic number, because the mean of its divisors is an integer number (5218555).

Almost surely, 2^20859973 is an apocalyptic number.

It is an amenable number.

20859973 is a deficient number, since it is larger than the sum of its proper divisors (14247).

20859973 is a wasteful number, since it uses less digits than its factorization.

20859973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14246.

The product of its (nonzero) digits is 136080, while the sum is 43.

The square root of 20859973 is about 4567.2719428560. The cubic root of 20859973 is about 275.2778371083.

The spelling of 20859973 in words is "twenty million, eight hundred fifty-nine thousand, nine hundred seventy-three".