91272089820 has 288 divisors, whose sum is σ = 279837347328. Its totient is φ = 22210449408.

The previous prime is 91272089801. The next prime is 91272089869. The reversal of 91272089820 is 2898027219.

It is a super-2 number, since 2×91272089820² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 91272089820.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 124518174 + ... + 124518906.

It is an arithmetic number, because the mean of its divisors is an integer number (971657456).

Almost surely, 2^91272089820 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91272089820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (139918673664).

91272089820 is an abundant number, since it is smaller than the sum of its proper divisors (188565257508).

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

91272089820 is a wasteful number, since it uses less digits than its factorization.

91272089820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 989 (or 970 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 48.

The spelling of 91272089820 in words is "ninety-one billion, two hundred seventy-two million, eighty-nine thousand, eight hundred twenty".