21674137 has 8 divisors (see below), whose sum is σ = 21918600. Its totient is φ = 21431424.

The previous prime is 21674129. The next prime is 21674141. The reversal of 21674137 is 73147612.

It can be written as a sum of positive squares in 4 ways, for example, as 8886361 + 12787776 = 2981^2 + 3576^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21674137 - 2³ = 21674129 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21674099 and 21674108.

It is not an unprimeable number, because it can be changed into a prime (21674197) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 52789 + ... + 53197.

It is an arithmetic number, because the mean of its divisors is an integer number (2739825).

Almost surely, 2^21674137 is an apocalyptic number.

It is an amenable number.

21674137 is a deficient number, since it is larger than the sum of its proper divisors (244463).

21674137 is a wasteful number, since it uses less digits than its factorization.

21674137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 875.

The product of its digits is 7056, while the sum is 31.

The square root of 21674137 is about 4655.5490546229. The cubic root of 21674137 is about 278.8135897610.

The spelling of 21674137 in words is "twenty-one million, six hundred seventy-four thousand, one hundred thirty-seven".