21376063 has 4 divisors (see below), whose sum is σ = 21394008. Its totient is φ = 21358120.

The previous prime is 21376051. The next prime is 21376067. The reversal of 21376063 is 36067312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21376063 - 2¹⁷ = 21244991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21376067) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 7048 + ... + 9613.

It is an arithmetic number, because the mean of its divisors is an integer number (5348502).

Almost surely, 2^21376063 is an apocalyptic number.

21376063 is a deficient number, since it is larger than the sum of its proper divisors (17945).

21376063 is a wasteful number, since it uses less digits than its factorization.

21376063 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17944.

The product of its (nonzero) digits is 4536, while the sum is 28.

The square root of 21376063 is about 4623.4254617113. The cubic root of 21376063 is about 277.5295556000.

The spelling of 21376063 in words is "twenty-one million, three hundred seventy-six thousand, sixty-three".