91400400 has 600 divisors, whose sum is σ = 416751104. Its totient is φ = 18662400.

The previous prime is 91400399. The next prime is 91400401. The reversal of 91400400 is 400419.

It is an interprime number because it is at equal distance from previous prime (91400399) and next prime (91400401).

It is a tau number, because it is divible by the number of its divisors (600).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91400401) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 2948385 + ... + 2948415.

Almost surely, 2^91400400 is an apocalyptic number.

91400400 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 91400400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (208375552).

91400400 is an abundant number, since it is smaller than the sum of its proper divisors (325350704).

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

91400400 is a wasteful number, since it uses less digits than its factorization.

91400400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81 (or 61 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 91400400 is about 9560.3556419204. The cubic root of 91400400 is about 450.4528774072.

Adding to 91400400 its reverse (400419), we get a palindrome (91800819).

The spelling of 91400400 in words is "ninety-one million, four hundred thousand, four hundred".