85401866221 has 6 divisors (see below), whose sum is σ = 99345028110. Its totient is φ = 73201599576.

The previous prime is 85401866189. The next prime is 85401866243. The reversal of 85401866221 is 12266810458.

It can be written as a sum of positive squares in only one way, i.e., 51444590596 + 33957275625 = 226814^2 + 184275^2 .

It is not a de Polignac number, because 85401866221 - 2⁵ = 85401866189 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 (85401866261) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 871447566 + ... + 871447663.

It is an arithmetic number, because the mean of its divisors is an integer number (16557504685).

Almost surely, 2^85401866221 is an apocalyptic number.

It is an amenable number.

85401866221 is a deficient number, since it is larger than the sum of its proper divisors (13943161889).

85401866221 is a wasteful number, since it uses less digits than its factorization.

85401866221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1742895243 (or 1742895236 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 43.

The spelling of 85401866221 in words is "eighty-five billion, four hundred one million, eight hundred sixty-six thousand, two hundred twenty-one".