83521187833861 has 4 divisors (see below), whose sum is σ = 83610324641452. Its totient is φ = 83432051026272.

The previous prime is 83521187833819. The next prime is 83521187833891. The reversal of 83521187833861 is 16833878112538.

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 37952869148100 + 45568318685761 = 6160590^2 + 6750431^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-83521187833861 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 83521187833793 and 83521187833802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (83521187833891) 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, 44568402390 + ... + 44568404263.

It is an arithmetic number, because the mean of its divisors is an integer number (20902581160363).

Almost surely, 2^{83521187833861} is an apocalyptic number.

It is an amenable number.

83521187833861 is a deficient number, since it is larger than the sum of its proper divisors (89136807591).

83521187833861 is an equidigital number, since it uses as much as digits as its factorization.

83521187833861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89136807590.

The product of its digits is 46448640, while the sum is 64.

The spelling of 83521187833861 in words is "eighty-three trillion, five hundred twenty-one billion, one hundred eighty-seven million, eight hundred thirty-three thousand, eight hundred sixty-one".