21104401 has 2 divisors, whose sum is σ = 21104402. Its totient is φ = 21104400.

The previous prime is 21104399. The next prime is 21104407. The reversal of 21104401 is 10440112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12110400 + 8994001 = 3480^2 + 2999^2 .

It is a cyclic number.

It is not a de Polignac number, because 21104401 - 2¹ = 21104399 is a prime.

Together with 21104399, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21104407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10552200 + 10552201.

It is an arithmetic number, because the mean of its divisors is an integer number (10552201).

Almost surely, 2^21104401 is an apocalyptic number.

It is an amenable number.

21104401 is a deficient number, since it is larger than the sum of its proper divisors (1).

21104401 is an equidigital number, since it uses as much as digits as its factorization.

21104401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 21104401 is about 4593.9526553938. The cubic root of 21104401 is about 276.3488596034.

Adding to 21104401 its reverse (10440112), we get a palindrome (31544513).

The spelling of 21104401 in words is "twenty-one million, one hundred four thousand, four hundred one".