21304401 has 16 divisors (see below), whose sum is σ = 28929600. Its totient is φ = 13943808.

The previous prime is 21304397. The next prime is 21304427. The reversal of 21304401 is 10440312.

21304401 is nontrivially palindromic in base 8.

21304401 is an esthetic number in base 8, because in such base its adjacent digits differ by 1.

It is not a de Polignac number, because 21304401 - 2² = 21304397 is a prime.

21304401 is an undulating number in base 8.

It is not an unprimeable number, because it can be changed into a prime (21304441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 51885 + ... + 52293.

It is an arithmetic number, because the mean of its divisors is an integer number (1808100).

Almost surely, 2^21304401 is an apocalyptic number.

It is an amenable number.

21304401 is a deficient number, since it is larger than the sum of its proper divisors (7625199).

21304401 is a wasteful number, since it uses less digits than its factorization.

21304401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 688.

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 21304401 is about 4615.6690739263. The cubic root of 21304401 is about 277.2190745210.

Adding to 21304401 its reverse (10440312), we get a palindrome (31744713).

The spelling of 21304401 in words is "twenty-one million, three hundred four thousand, four hundred one".