91020020211 has 6 divisors (see below), whose sum is σ = 131473362540. Its totient is φ = 60680013468.

The previous prime is 91020020191. The next prime is 91020020227. The reversal of 91020020211 is 11202002019.

It is not a de Polignac number, because 91020020211 - 2¹⁴ = 91020003827 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91020020261) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5056667781 + ... + 5056667798.

It is an arithmetic number, because the mean of its divisors is an integer number (21912227090).

Almost surely, 2^91020020211 is an apocalyptic number.

91020020211 is a deficient number, since it is larger than the sum of its proper divisors (40453342329).

91020020211 is a wasteful number, since it uses less digits than its factorization.

91020020211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10113335585 (or 10113335582 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The spelling of 91020020211 in words is "ninety-one billion, twenty million, twenty thousand, two hundred eleven".