91938420 has 144 divisors (see below), whose sum is σ = 321729408. Its totient is φ = 20816640.

The previous prime is 91938389. The next prime is 91938421. The reversal of 91938420 is 2483919.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91938421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 164782 + ... + 165338.

It is an arithmetic number, because the mean of its divisors is an integer number (2234232).

Almost surely, 2^91938420 is an apocalyptic number.

91938420 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91938420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (160864704).

91938420 is an abundant number, since it is smaller than the sum of its proper divisors (229790988).

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

91938420 is a wasteful number, since it uses less digits than its factorization.

91938420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 710 (or 705 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 91938420 is about 9588.4524298763. The cubic root of 91938420 is about 451.3349985551.

The spelling of 91938420 in words is "ninety-one million, nine hundred thirty-eight thousand, four hundred twenty".