21100801 has 8 divisors (see below), whose sum is σ = 21835008. Its totient is φ = 20370000.

The previous prime is 21100789. The next prime is 21100813. The reversal of 21100801 is 10800112.

It is an interprime number because it is at equal distance from previous prime (21100789) and next prime (21100813).

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 21100801 - 2⁵ = 21100769 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21100601) 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, 21246 + ... + 22216.

It is an arithmetic number, because the mean of its divisors is an integer number (2729376).

Almost surely, 2^21100801 is an apocalyptic number.

It is an amenable number.

21100801 is a deficient number, since it is larger than the sum of its proper divisors (734207).

21100801 is an equidigital number, since it uses as much as digits as its factorization.

21100801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1703.

The product of its (nonzero) digits is 16, while the sum is 13.

The square root of 21100801 is about 4593.5608192338. The cubic root of 21100801 is about 276.3331454645. Note that the first 3 decimals are identical.

Adding to 21100801 its reverse (10800112), we get a palindrome (31900913).

The spelling of 21100801 in words is "twenty-one million, one hundred thousand, eight hundred one".