21847801 has 4 divisors (see below), whose sum is σ = 22007412. Its totient is φ = 21688192.

The previous prime is 21847783. The next prime is 21847823. The reversal of 21847801 is 10874812.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6007401 + 15840400 = 2451^2 + 3980^2 .

It is a cyclic number.

It is not a de Polignac number, because 21847801 - 2¹⁵ = 21815033 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21847831) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 79600 + ... + 79873.

It is an arithmetic number, because the mean of its divisors is an integer number (5501853).

Almost surely, 2^21847801 is an apocalyptic number.

It is an amenable number.

21847801 is a deficient number, since it is larger than the sum of its proper divisors (159611).

21847801 is a wasteful number, since it uses less digits than its factorization.

21847801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159610.

The product of its (nonzero) digits is 3584, while the sum is 31.

The square root of 21847801 is about 4674.1631336529. The cubic root of 21847801 is about 279.5562742245.

The spelling of 21847801 in words is "twenty-one million, eight hundred forty-seven thousand, eight hundred one".