85780205621 has 4 divisors (see below), whose sum is σ = 93578406144. Its totient is φ = 77982005100.

The previous prime is 85780205587. The next prime is 85780205627. The reversal of 85780205621 is 12650208758.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 85780205621 - 2²⁶ = 85713096757 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 (85780205627) 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, 3899100245 + ... + 3899100266.

It is an arithmetic number, because the mean of its divisors is an integer number (23394601536).

Almost surely, 2^85780205621 is an apocalyptic number.

It is an amenable number.

85780205621 is a deficient number, since it is larger than the sum of its proper divisors (7798200523).

85780205621 is a wasteful number, since it uses less digits than its factorization.

85780205621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7798200522.

The product of its (nonzero) digits is 268800, while the sum is 44.

The spelling of 85780205621 in words is "eighty-five billion, seven hundred eighty million, two hundred five thousand, six hundred twenty-one".