91000428 has 24 divisors (see below), whose sum is σ = 212694720. Its totient is φ = 30282000.

The previous prime is 91000423. The next prime is 91000451. The reversal of 91000428 is 82400019.

It is a junction number, because it is equal to n+sod(n) for n = 91000398 and 91000407.

It is not an unprimeable number, because it can be changed into a prime (91000421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1303 + ... + 13553.

It is an arithmetic number, because the mean of its divisors is an integer number (8862280).

Almost surely, 2^91000428 is an apocalyptic number.

It is an amenable number.

91000428 is an abundant number, since it is smaller than the sum of its proper divisors (121694292).

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

91000428 is a wasteful number, since it uses less digits than its factorization.

91000428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12877 (or 12875 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 91000428 is about 9539.4144474386. The cubic root of 91000428 is about 449.7948496982.

The spelling of 91000428 in words is "ninety-one million, four hundred twenty-eight", and thus it is an aban number.