21369686 has 8 divisors (see below), whose sum is σ = 34520304. Its totient is φ = 9862920.

The previous prime is 21369679. The next prime is 21369709. The reversal of 21369686 is 68696312.

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

It is a congruent number.

It is an unprimeable number.

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, 410930 + ... + 410981.

It is an arithmetic number, because the mean of its divisors is an integer number (4315038).

Almost surely, 2^21369686 is an apocalyptic number.

21369686 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21369686 is a deficient number, since it is larger than the sum of its proper divisors (13150618).

21369686 is a wasteful number, since it uses less digits than its factorization.

21369686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 821926.

The product of its digits is 93312, while the sum is 41.

The square root of 21369686 is about 4622.7357700825. The cubic root of 21369686 is about 277.5019549141.

It can be divided in two parts, 2 and 1369686, that multiplied together give a palindrome (2739372).

The spelling of 21369686 in words is "twenty-one million, three hundred sixty-nine thousand, six hundred eighty-six".