21471679 has 4 divisors (see below), whose sum is σ = 21481200. Its totient is φ = 21462160.

The previous prime is 21471677. The next prime is 21471701. The reversal of 21471679 is 97617412.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21471679 - 2¹ = 21471677 is a prime.

It is a super-2 number, since 2×21471679² = 922065998158082, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21471677) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 747 + ... + 6595.

It is an arithmetic number, because the mean of its divisors is an integer number (5370300).

Almost surely, 2^21471679 is an apocalyptic number.

21471679 is a deficient number, since it is larger than the sum of its proper divisors (9521).

21471679 is an equidigital number, since it uses as much as digits as its factorization.

21471679 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9520.

The product of its digits is 21168, while the sum is 37.

The square root of 21471679 is about 4633.7543094126. The cubic root of 21471679 is about 277.9427404801.

The spelling of 21471679 in words is "twenty-one million, four hundred seventy-one thousand, six hundred seventy-nine".