21396355 has 8 divisors (see below), whose sum is σ = 26504064. Its totient is φ = 16564800.

The previous prime is 21396317. The next prime is 21396379. The reversal of 21396355 is 55369312.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21396355 - 2¹⁹ = 20872067 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21396355.

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 in 7 ways as a sum of consecutive naturals, for example, 68866 + ... + 69175.

It is an arithmetic number, because the mean of its divisors is an integer number (3313008).

Almost surely, 2^21396355 is an apocalyptic number.

21396355 is a deficient number, since it is larger than the sum of its proper divisors (5107709).

21396355 is a wasteful number, since it uses less digits than its factorization.

21396355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138077.

The product of its digits is 24300, while the sum is 34.

The square root of 21396355 is about 4625.6194179807. The cubic root of 21396355 is about 277.6173461451.

The spelling of 21396355 in words is "twenty-one million, three hundred ninety-six thousand, three hundred fifty-five".