21610001 has 8 divisors (see below), whose sum is σ = 24975360. Its totient is φ = 18314208.

The previous prime is 21609977. The next prime is 21610003. The reversal of 21610001 is 10001612.

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 21610001 - 2⁶ = 21609937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21610003) 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, 16721 + ... + 17966.

It is an arithmetic number, because the mean of its divisors is an integer number (3121920).

Almost surely, 2^21610001 is an apocalyptic number.

It is an amenable number.

21610001 is a deficient number, since it is larger than the sum of its proper divisors (3365359).

21610001 is an equidigital number, since it uses as much as digits as its factorization.

21610001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34783.

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 21610001 is about 4648.6558272258. The cubic root of 21610001 is about 278.5383053569.

Adding to 21610001 its reverse (10001612), we get a palindrome (31611613).

The spelling of 21610001 in words is "twenty-one million, six hundred ten thousand, one".