21869853 has 8 divisors (see below), whose sum is σ = 29181408. Its totient is φ = 14569104.

The previous prime is 21869839. The next prime is 21869879. The reversal of 21869853 is 35896812.

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

It is not a de Polignac number, because 21869853 - 2⁵ = 21869821 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21869153) 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, 6726 + ... + 9432.

It is an arithmetic number, because the mean of its divisors is an integer number (3647676).

Almost surely, 2^21869853 is an apocalyptic number.

It is an amenable number.

21869853 is a deficient number, since it is larger than the sum of its proper divisors (7311555).

21869853 is a wasteful number, since it uses less digits than its factorization.

21869853 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5403.

The product of its digits is 103680, while the sum is 42.

The square root of 21869853 is about 4676.5214636522. The cubic root of 21869853 is about 279.6502989732.

It can be divided in two parts, 21869 and 853, that added together give a palindrome (22722).

The spelling of 21869853 in words is "twenty-one million, eight hundred sixty-nine thousand, eight hundred fifty-three".