21854879 has 8 divisors (see below), whose sum is σ = 22471680. Its totient is φ = 21243096.

The previous prime is 21854869. The next prime is 21854887. The reversal of 21854879 is 97845812.

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 21854879 - 2¹² = 21850783 is a prime.

It is a super-2 number, since 2×21854879² = 955271472209282, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21854869) 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, 8642 + ... + 10880.

It is an arithmetic number, because the mean of its divisors is an integer number (2808960).

Almost surely, 2^21854879 is an apocalyptic number.

21854879 is a deficient number, since it is larger than the sum of its proper divisors (616801).

21854879 is a wasteful number, since it uses less digits than its factorization.

21854879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2509.

The product of its digits is 161280, while the sum is 44.

The square root of 21854879 is about 4674.9202132229. The cubic root of 21854879 is about 279.5864601102.

The spelling of 21854879 in words is "twenty-one million, eight hundred fifty-four thousand, eight hundred seventy-nine".