27806212421 has 4 divisors (see below), whose sum is σ = 29945151852. Its totient is φ = 25667272992.

The previous prime is 27806212391. The next prime is 27806212433. The reversal of 27806212421 is 12421260872.

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 6247163521 + 21559048900 = 79039^2 + 146830^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27806212421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27806212471) 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, 1069469696 + ... + 1069469721.

It is an arithmetic number, because the mean of its divisors is an integer number (7486287963).

Almost surely, 2^27806212421 is an apocalyptic number.

It is an amenable number.

27806212421 is a deficient number, since it is larger than the sum of its proper divisors (2138939431).

27806212421 is a wasteful number, since it uses less digits than its factorization.

27806212421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2138939430.

The product of its (nonzero) digits is 21504, while the sum is 35.

The spelling of 27806212421 in words is "twenty-seven billion, eight hundred six million, two hundred twelve thousand, four hundred twenty-one".