27821720685 has 32 divisors (see below), whose sum is σ = 51418115712. Its totient is φ = 12695828480.

The previous prime is 27821720683. The next prime is 27821720687. The reversal of 27821720685 is 58602712872.

It is an interprime number because it is at equal distance from previous prime (27821720683) and next prime (27821720687).

It is not a de Polignac number, because 27821720685 - 2¹ = 27821720683 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27821720683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4956504 + ... + 4962113.

It is an arithmetic number, because the mean of its divisors is an integer number (1606816116).

Almost surely, 2^27821720685 is an apocalyptic number.

It is an amenable number.

27821720685 is a deficient number, since it is larger than the sum of its proper divisors (23596395027).

27821720685 is a wasteful number, since it uses less digits than its factorization.

27821720685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9918653.

The product of its (nonzero) digits is 752640, while the sum is 48.

The spelling of 27821720685 in words is "twenty-seven billion, eight hundred twenty-one million, seven hundred twenty thousand, six hundred eighty-five".