91212010013 has 4 divisors (see below), whose sum is σ = 92932991388. Its totient is φ = 89491028640.

The previous prime is 91212010003. The next prime is 91212010031. The reversal of 91212010013 is 31001021219.

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 42412107364 + 48799902649 = 205942^2 + 220907^2 .

It is a cyclic number.

It is not a de Polignac number, because 91212010013 - 2²⁰ = 91210961437 is a prime.

It is a super-2 number, since 2×91212010013² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91212010003) 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, 860490608 + ... + 860490713.

It is an arithmetic number, because the mean of its divisors is an integer number (23233247847).

Almost surely, 2^91212010013 is an apocalyptic number.

It is an amenable number.

91212010013 is a deficient number, since it is larger than the sum of its proper divisors (1720981375).

91212010013 is a wasteful number, since it uses less digits than its factorization.

91212010013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1720981374.

The product of its (nonzero) digits is 108, while the sum is 20.

The spelling of 91212010013 in words is "ninety-one billion, two hundred twelve million, ten thousand, thirteen".