21407683 has 6 divisors (see below), whose sum is σ = 23530892. Its totient is φ = 19461420.

The previous prime is 21407681. The next prime is 21407693. The reversal of 21407683 is 38670412.

It is not a de Polignac number, because 21407683 - 2¹ = 21407681 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21407681) 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 5 ways as a sum of consecutive naturals, for example, 88341 + ... + 88582.

Almost surely, 2^21407683 is an apocalyptic number.

21407683 is a deficient number, since it is larger than the sum of its proper divisors (2123209).

21407683 is a wasteful number, since it uses less digits than its factorization.

21407683 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176945 (or 176934 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 21407683 is about 4626.8437406076. The cubic root of 21407683 is about 277.6663310378. Note that the first 3 decimals are identical.

It can be divided in two parts, 21 and 407683, that added together give a palindrome (407704).

The spelling of 21407683 in words is "twenty-one million, four hundred seven thousand, six hundred eighty-three".