21386763 has 12 divisors (see below), whose sum is σ = 30968080. Its totient is φ = 14222736.

The previous prime is 21386759. The next prime is 21386773. The reversal of 21386763 is 36768312.

It is a happy number.

It is not a de Polignac number, because 21386763 - 2² = 21386759 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21386713) 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 11 ways as a sum of consecutive naturals, for example, 1245 + ... + 6657.

Almost surely, 2^21386763 is an apocalyptic number.

21386763 is a deficient number, since it is larger than the sum of its proper divisors (9581317).

21386763 is a wasteful number, since it uses less digits than its factorization.

21386763 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5858 (or 5855 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 21386763 is about 4624.5824676396. The cubic root of 21386763 is about 277.5758545981.

The spelling of 21386763 in words is "twenty-one million, three hundred eighty-six thousand, seven hundred sixty-three".