21363776 has 56 divisors (see below), whose sum is σ = 49621440. Its totient is φ = 8934912.

The previous prime is 21363773. The next prime is 21363779. The reversal of 21363776 is 67736312.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21363773) and next prime (21363779).

It is a tau number, because it is divible by the number of its divisors (56).

It is not an unprimeable number, because it can be changed into a prime (21363773) 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 7 ways as a sum of consecutive naturals, for example, 18710 + ... + 19818.

Almost surely, 2^21363776 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21363776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24810720).

21363776 is an abundant number, since it is smaller than the sum of its proper divisors (28257664).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21363776 is a wasteful number, since it uses less digits than its factorization.

21363776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1171 (or 1161 counting only the distinct ones).

The product of its digits is 31752, while the sum is 35.

The square root of 21363776 is about 4622.0964940165. The cubic root of 21363776 is about 277.4763705768.

The spelling of 21363776 in words is "twenty-one million, three hundred sixty-three thousand, seven hundred seventy-six".