21446401 has 6 divisors (see below), whose sum is σ = 22782470. Its totient is φ = 20184576.

The previous prime is 21446387. The next prime is 21446407. The reversal of 21446401 is 10464412.

It can be written as a sum of positive squares in 3 ways, for example, as 15681600 + 5764801 = 3960^2 + 2401^2 .

It is a de Polignac number, because none of the positive numbers 2^k-21446401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21446407) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 36816 + ... + 37393.

Almost surely, 2^21446401 is an apocalyptic number.

It is an amenable number.

21446401 is a deficient number, since it is larger than the sum of its proper divisors (1336069).

21446401 is an equidigital number, since it uses as much as digits as its factorization.

21446401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74243 (or 74226 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 21446401 is about 4631.0259122575. The cubic root of 21446401 is about 277.8336262758.

The spelling of 21446401 in words is "twenty-one million, four hundred forty-six thousand, four hundred one".