21679377 has 8 divisors (see below), whose sum is σ = 29176416. Its totient is φ = 14317632.

The previous prime is 21679367. The next prime is 21679379. The reversal of 21679377 is 77397612.

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

It is not a de Polignac number, because 21679377 - 2⁷ = 21679249 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21679379) 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, 33448 + ... + 34089.

It is an arithmetic number, because the mean of its divisors is an integer number (3647052).

Almost surely, 2^21679377 is an apocalyptic number.

It is an amenable number.

21679377 is a deficient number, since it is larger than the sum of its proper divisors (7497039).

21679377 is a wasteful number, since it uses less digits than its factorization.

21679377 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67647.

The product of its digits is 111132, while the sum is 42.

The square root of 21679377 is about 4656.1117898951. Note that the first 3 decimals coincide. The cubic root of 21679377 is about 278.8360568683.

The spelling of 21679377 in words is "twenty-one million, six hundred seventy-nine thousand, three hundred seventy-seven".