91122780 has 96 divisors (see below), whose sum is σ = 304303104. Its totient is φ = 19920384.

The previous prime is 91122767. The next prime is 91122793. The reversal of 91122780 is 8722119.

It is an interprime number because it is at equal distance from previous prime (91122767) and next prime (91122793).

It is a super-2 number, since 2×91122780² = 16606722069856800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4944 + ... + 14376.

It is an arithmetic number, because the mean of its divisors is an integer number (3169824).

Almost surely, 2^91122780 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 91122780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (152151552).

91122780 is an abundant number, since it is smaller than the sum of its proper divisors (213180324).

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

91122780 is a wasteful number, since it uses less digits than its factorization.

91122780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9475 (or 9473 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 91122780 is about 9545.8252655284. The cubic root of 91122780 is about 449.9963456493.

Adding to 91122780 its reverse (8722119), we get a palindrome (99844899).

The spelling of 91122780 in words is "ninety-one million, one hundred twenty-two thousand, seven hundred eighty".