21838081 has 8 divisors (see below), whose sum is σ = 23228640. Its totient is φ = 20459328.

The previous prime is 21838057. The next prime is 21838099. The reversal of 21838081 is 18083812.

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 21838081 - 2¹⁹ = 21313793 is a prime.

It is a super-2 number, since 2×21838081² = 953803563525122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21838001) 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, 1030 + ... + 6688.

It is an arithmetic number, because the mean of its divisors is an integer number (2903580).

Almost surely, 2^21838081 is an apocalyptic number.

It is an amenable number.

21838081 is a deficient number, since it is larger than the sum of its proper divisors (1390559).

21838081 is a wasteful number, since it uses less digits than its factorization.

21838081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5903.

The product of its (nonzero) digits is 3072, while the sum is 31.

The square root of 21838081 is about 4673.1232596626. The cubic root of 21838081 is about 279.5148102491.

The spelling of 21838081 in words is "twenty-one million, eight hundred thirty-eight thousand, eighty-one".