21386633 has 4 divisors (see below), whose sum is σ = 21404880. Its totient is φ = 21368388.

The previous prime is 21386623. The next prime is 21386639. The reversal of 21386633 is 33668312.

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 21386633 - 2¹⁴ = 21370249 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 21386633.

It is not an unprimeable number, because it can be changed into a prime (21386639) 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, 7235 + ... + 9752.

It is an arithmetic number, because the mean of its divisors is an integer number (5351220).

Almost surely, 2^21386633 is an apocalyptic number.

It is an amenable number.

21386633 is a deficient number, since it is larger than the sum of its proper divisors (18247).

21386633 is a wasteful number, since it uses less digits than its factorization.

21386633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18246.

The product of its digits is 15552, while the sum is 32.

The square root of 21386633 is about 4624.5684122954. The cubic root of 21386633 is about 277.5752921795.

The spelling of 21386633 in words is "twenty-one million, three hundred eighty-six thousand, six hundred thirty-three".