21206712001 has 2 divisors, whose sum is σ = 21206712002. Its totient is φ = 21206712000.

The previous prime is 21206711993. The next prime is 21206712017. The reversal of 21206712001 is 10021760212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16595622976 + 4611089025 = 128824^2 + 67905^2 .

It is a cyclic number.

It is not a de Polignac number, because 21206712001 - 2³ = 21206711993 is a prime.

It is a super-3 number, since 3×21206712001³ (a number of 32 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (21206712061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10603356000 + 10603356001.

It is an arithmetic number, because the mean of its divisors is an integer number (10603356001).

Almost surely, 2^21206712001 is an apocalyptic number.

It is an amenable number.

21206712001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21206712001 is an equidigital number, since it uses as much as digits as its factorization.

21206712001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 336, while the sum is 22.

The spelling of 21206712001 in words is "twenty-one billion, two hundred six million, seven hundred twelve thousand, one".