85137901551221 has 2 divisors, whose sum is σ = 85137901551222. Its totient is φ = 85137901551220.

The previous prime is 85137901551193. The next prime is 85137901551299. The reversal of 85137901551221 is 12215510973158.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 84045604834321 + 1092296716900 = 9167639^2 + 1045130^2 .

It is a cyclic number.

It is not a de Polignac number, because 85137901551221 - 2¹⁰ = 85137901550197 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 85137901551221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85137901581221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42568950775610 + 42568950775611.

It is an arithmetic number, because the mean of its divisors is an integer number (42568950775611).

Almost surely, 2^{85137901551221} is an apocalyptic number.

It is an amenable number.

85137901551221 is a deficient number, since it is larger than the sum of its proper divisors (1).

85137901551221 is an equidigital number, since it uses as much as digits as its factorization.

85137901551221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 756000, while the sum is 50.

The spelling of 85137901551221 in words is "eighty-five trillion, one hundred thirty-seven billion, nine hundred one million, five hundred fifty-one thousand, two hundred twenty-one".