21637085 has 8 divisors (see below), whose sum is σ = 26043576. Its totient is φ = 17256960.

The previous prime is 21637069. The next prime is 21637093. The reversal of 21637085 is 58073612.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 743044 + 20894041 = 862^2 + 4571^2 .

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

It is not a de Polignac number, because 21637085 - 2⁴ = 21637069 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4736 + ... + 8105.

It is an arithmetic number, because the mean of its divisors is an integer number (3255447).

Almost surely, 2^21637085 is an apocalyptic number.

It is an amenable number.

21637085 is a deficient number, since it is larger than the sum of its proper divisors (4406491).

21637085 is a wasteful number, since it uses less digits than its factorization.

21637085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13183.

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 21637085 is about 4651.5680151966. The cubic root of 21637085 is about 278.6546215945.

The spelling of 21637085 in words is "twenty-one million, six hundred thirty-seven thousand, eighty-five".