21677973 has 8 divisors (see below), whose sum is σ = 28925568. Its totient is φ = 14441184.

The previous prime is 21677969. The next prime is 21677987. The reversal of 21677973 is 37977612.

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

It is not a de Polignac number, because 21677973 - 2² = 21677969 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21677923) 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 7 ways as a sum of consecutive naturals, for example, 5865 + ... + 8817.

It is an arithmetic number, because the mean of its divisors is an integer number (3615696).

Almost surely, 2^21677973 is an apocalyptic number.

It is an amenable number.

21677973 is a deficient number, since it is larger than the sum of its proper divisors (7247595).

21677973 is a wasteful number, since it uses less digits than its factorization.

21677973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5403.

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

The square root of 21677973 is about 4655.9610178780. The cubic root of 21677973 is about 278.8300374107.

The spelling of 21677973 in words is "twenty-one million, six hundred seventy-seven thousand, nine hundred seventy-three".