91003878 has 96 divisors (see below), whose sum is σ = 237813120. Its totient is φ = 25719120.

The previous prime is 91003877. The next prime is 91003903. The reversal of 91003878 is 87830019.

It is a super-2 number, since 2×91003878² = 16563411622077768, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91003877) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 431193 + ... + 431403.

It is an arithmetic number, because the mean of its divisors is an integer number (2477220).

Almost surely, 2^91003878 is an apocalyptic number.

91003878 is a gapful number since it is divisible by the number (98) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 91003878, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118906560).

91003878 is an abundant number, since it is smaller than the sum of its proper divisors (146809242).

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

91003878 is a wasteful number, since it uses less digits than its factorization.

91003878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 399 (or 386 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 91003878 is about 9539.5952744338. The cubic root of 91003878 is about 449.8005338203.

It can be divided in two parts, 910038 and 78, that added together give a square (910116 = 954²).

The spelling of 91003878 in words is "ninety-one million, three thousand, eight hundred seventy-eight".