21213610642001 has 4 divisors (see below), whose sum is σ = 21213622552500. Its totient is φ = 21213598731504.

The previous prime is 21213610641943. The next prime is 21213610642043. The reversal of 21213610642001 is 10024601631212.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 3537976664401 + 17675633977600 = 1880951^2 + 4204240^2 .

It is a cyclic number.

It is not a de Polignac number, because 21213610642001 - 2³⁴ = 21196430772817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21213610632001) 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, 2685026 + ... + 7045323.

It is an arithmetic number, because the mean of its divisors is an integer number (5303405638125).

Almost surely, 2^{21213610642001} is an apocalyptic number.

It is an amenable number.

21213610642001 is a deficient number, since it is larger than the sum of its proper divisors (11910499).

21213610642001 is an equidigital number, since it uses as much as digits as its factorization.

21213610642001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11910498.

The product of its (nonzero) digits is 3456, while the sum is 29.

The spelling of 21213610642001 in words is "twenty-one trillion, two hundred thirteen billion, six hundred ten million, six hundred forty-two thousand, one".