21403401 has 4 divisors (see below), whose sum is σ = 28537872. Its totient is φ = 14268932.

The previous prime is 21403399. The next prime is 21403433. The reversal of 21403401 is 10430412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21403401 - 2¹ = 21403399 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21403441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3567231 + ... + 3567236.

It is an arithmetic number, because the mean of its divisors is an integer number (7134468).

Almost surely, 2^21403401 is an apocalyptic number.

It is an amenable number.

21403401 is a deficient number, since it is larger than the sum of its proper divisors (7134471).

21403401 is an equidigital number, since it uses as much as digits as its factorization.

21403401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7134470.

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

The square root of 21403401 is about 4626.3809830147. The cubic root of 21403401 is about 277.6478167111.

Adding to 21403401 its reverse (10430412), we get a palindrome (31833813).

The spelling of 21403401 in words is "twenty-one million, four hundred three thousand, four hundred one".