85780216821121 has 9 divisors (see below), whose sum is σ = 87259317073761. Its totient is φ = 84325777658964.

The previous prime is 85780216821107. The next prime is 85780216821139. The reversal of 85780216821121 is 12112861208758.

The square root of 85780216821121 is 9261761.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 85780216821121 - 2²¹ = 85780214723969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (85780216891121) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 546365410 + ... + 546522388.

Almost surely, 2^{85780216821121} is an apocalyptic number.

85780216821121 is the 9261761-st square number.

85780216821121 is the 4630881-st centered octagonal number.

It is an amenable number.

85780216821121 is a deficient number, since it is larger than the sum of its proper divisors (1479100252640).

85780216821121 is an frugal number, since it uses more digits than its factorization.

85780216821121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314076 (or 157038 counting only the distinct ones).

The product of its (nonzero) digits is 860160, while the sum is 52.

The spelling of 85780216821121 in words is "eighty-five trillion, seven hundred eighty billion, two hundred sixteen million, eight hundred twenty-one thousand, one hundred twenty-one".