21868001 has 8 divisors (see below), whose sum is σ = 23953320. Its totient is φ = 19871488.

The previous prime is 21867983. The next prime is 21868013. The reversal of 21868001 is 10086812.

It can be written as a sum of positive squares in 4 ways, for example, as 11723776 + 10144225 = 3424^2 + 3185^2 .

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 21868001 - 2²² = 17673697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21868081) 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, 21686 + ... + 22671.

It is an arithmetic number, because the mean of its divisors is an integer number (2994165).

Almost surely, 2^21868001 is an apocalyptic number.

It is an amenable number.

21868001 is a deficient number, since it is larger than the sum of its proper divisors (2085319).

21868001 is a wasteful number, since it uses less digits than its factorization.

21868001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44403.

The product of its (nonzero) digits is 768, while the sum is 26.

The square root of 21868001 is about 4676.3234490356. The cubic root of 21868001 is about 279.6424048952.

The spelling of 21868001 in words is "twenty-one million, eight hundred sixty-eight thousand, one".