21266023001 has 4 divisors (see below), whose sum is σ = 21667268772. Its totient is φ = 20864777232.

The previous prime is 21266022979. The next prime is 21266023003. The reversal of 21266023001 is 10032066212.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6548693776 + 14717329225 = 80924^2 + 121315^2 .

It is a cyclic number.

It is not a de Polignac number, because 21266023001 - 2⁶ = 21266022937 is a prime.

It is a super-2 number, since 2×21266023001² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21266023003) 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, 200622806 + ... + 200622911.

It is an arithmetic number, because the mean of its divisors is an integer number (5416817193).

Almost surely, 2^21266023001 is an apocalyptic number.

It is an amenable number.

21266023001 is a deficient number, since it is larger than the sum of its proper divisors (401245771).

21266023001 is an equidigital number, since it uses as much as digits as its factorization.

21266023001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 401245770.

The product of its (nonzero) digits is 864, while the sum is 23.

Adding to 21266023001 its reverse (10032066212), we get a palindrome (31298089213).

The spelling of 21266023001 in words is "twenty-one billion, two hundred sixty-six million, twenty-three thousand, one".