21799853 has 4 divisors (see below), whose sum is σ = 21909600. Its totient is φ = 21690108.

The previous prime is 21799849. The next prime is 21799871. The reversal of 21799853 is 35899712.

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 21799853 - 2² = 21799849 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 (21799153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54575 + ... + 54972.

It is an arithmetic number, because the mean of its divisors is an integer number (5477400).

Almost surely, 2^21799853 is an apocalyptic number.

It is an amenable number.

21799853 is a deficient number, since it is larger than the sum of its proper divisors (109747).

21799853 is a wasteful number, since it uses less digits than its factorization.

21799853 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109746.

The product of its digits is 136080, while the sum is 44.

The square root of 21799853 is about 4669.0312699745. The cubic root of 21799853 is about 279.3516162215.

The spelling of 21799853 in words is "twenty-one million, seven hundred ninety-nine thousand, eight hundred fifty-three".