91212121212 has 48 divisors (see below), whose sum is σ = 213897477024. Its totient is φ = 30251520000.

The previous prime is 91212121141. The next prime is 91212121213. The reversal of 91212121212 is 21212121219.

91212121212 is a modest number, since divided by 121212 gives 91212 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91212121213) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3460162 + ... + 3486422.

It is an arithmetic number, because the mean of its divisors is an integer number (4456197438).

Almost surely, 2^91212121212 is an apocalyptic number.

It is an amenable number.

91212121212 is an abundant number, since it is smaller than the sum of its proper divisors (122685355812).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91212121212 is a wasteful number, since it uses less digits than its factorization.

91212121212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27710 (or 27708 counting only the distinct ones).

The product of its digits is 288, while the sum is 24.

The spelling of 91212121212 in words is "ninety-one billion, two hundred twelve million, one hundred twenty-one thousand, two hundred twelve".