21354331 has 8 divisors (see below), whose sum is σ = 21798704. Its totient is φ = 20913120.

The previous prime is 21354301. The next prime is 21354337. The reversal of 21354331 is 13345312.

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 21354331 - 2¹⁵ = 21321563 is a prime.

It is a super-2 number, since 2×21354331² = 912014904915122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21354337) 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, 16645 + ... + 17881.

It is an arithmetic number, because the mean of its divisors is an integer number (2724838).

Almost surely, 2^21354331 is an apocalyptic number.

21354331 is a deficient number, since it is larger than the sum of its proper divisors (444373).

21354331 is a wasteful number, since it uses less digits than its factorization.

21354331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1581.

The product of its digits is 1080, while the sum is 22.

The square root of 21354331 is about 4621.0746585616. The cubic root of 21354331 is about 277.4354734584.

Adding to 21354331 its reverse (13345312), we get a palindrome (34699643).

The spelling of 21354331 in words is "twenty-one million, three hundred fifty-four thousand, three hundred thirty-one".