21712827 has 4 divisors (see below), whose sum is σ = 28950440. Its totient is φ = 14475216.

The previous prime is 21712819. The next prime is 21712843. The reversal of 21712827 is 72821712.

It is a happy number.

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

It is not a de Polignac number, because 21712827 - 2³ = 21712819 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21712794 and 21712803.

It is not an unprimeable number, because it can be changed into a prime (21711827) 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, 3618802 + ... + 3618807.

It is an arithmetic number, because the mean of its divisors is an integer number (7237610).

Almost surely, 2^21712827 is an apocalyptic number.

21712827 is a deficient number, since it is larger than the sum of its proper divisors (7237613).

21712827 is an equidigital number, since it uses as much as digits as its factorization.

21712827 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7237612.

The product of its digits is 3136, while the sum is 30.

The square root of 21712827 is about 4659.7024583121. The cubic root of 21712827 is about 278.9793923706.

The spelling of 21712827 in words is "twenty-one million, seven hundred twelve thousand, eight hundred twenty-seven".