21446851 has 4 divisors (see below), whose sum is σ = 21503232. Its totient is φ = 21390472.

The previous prime is 21446849. The next prime is 21446857. The reversal of 21446851 is 15864412.

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

It is a cyclic number.

It is not a de Polignac number, because 21446851 - 2¹ = 21446849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21446857) 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, 27616 + ... + 28381.

It is an arithmetic number, because the mean of its divisors is an integer number (5375808).

Almost surely, 2^21446851 is an apocalyptic number.

21446851 is a deficient number, since it is larger than the sum of its proper divisors (56381).

21446851 is an equidigital number, since it uses as much as digits as its factorization.

21446851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56380.

The product of its digits is 7680, while the sum is 31.

The square root of 21446851 is about 4631.0744973494. The cubic root of 21446851 is about 277.8355694808.

The spelling of 21446851 in words is "twenty-one million, four hundred forty-six thousand, eight hundred fifty-one".