21403366 has 4 divisors (see below), whose sum is σ = 32105052. Its totient is φ = 10701682.

The previous prime is 21403337. The next prime is 21403399. The reversal of 21403366 is 66330412.

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

It is a super-2 number, since 2×21403366² = 916208152259912, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21403366.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5350840 + ... + 5350843.

It is an arithmetic number, because the mean of its divisors is an integer number (8026263).

Almost surely, 2^21403366 is an apocalyptic number.

21403366 is a deficient number, since it is larger than the sum of its proper divisors (10701686).

21403366 is a wasteful number, since it uses less digits than its factorization.

21403366 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10701685.

The product of its (nonzero) digits is 2592, while the sum is 25.

The square root of 21403366 is about 4626.3772003588. The cubic root of 21403366 is about 277.6476653694.

Adding to 21403366 its reverse (66330412), we get a palindrome (87733778).

The spelling of 21403366 in words is "twenty-one million, four hundred three thousand, three hundred sixty-six".