21674971 has 4 divisors (see below), whose sum is σ = 21918600. Its totient is φ = 21431344.

The previous prime is 21674957. The next prime is 21674981. The reversal of 21674971 is 17947612.

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

It is a cyclic number.

It is not a de Polignac number, because 21674971 - 2¹³ = 21666779 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21674971.

It is not an unprimeable number, because it can be changed into a prime (21674911) 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, 121681 + ... + 121858.

It is an arithmetic number, because the mean of its divisors is an integer number (5479650).

Almost surely, 2^21674971 is an apocalyptic number.

21674971 is a deficient number, since it is larger than the sum of its proper divisors (243629).

21674971 is an equidigital number, since it uses as much as digits as its factorization.

21674971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243628.

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

The square root of 21674971 is about 4655.6386242921. The cubic root of 21674971 is about 278.8171658749.

The spelling of 21674971 in words is "twenty-one million, six hundred seventy-four thousand, nine hundred seventy-one".