45991440 has 120 divisors (see below), whose sum is σ = 168524928. Its totient is φ = 11147520.

The previous prime is 45991433. The next prime is 45991441. The reversal of 45991440 is 4419954.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (120).

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

It is a junction number, because it is equal to n+sod(n) for n = 45991395 and 45991404.

It is not an unprimeable number, because it can be changed into a prime (45991441) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5017 + ... + 10823.

Almost surely, 2^45991440 is an apocalyptic number.

45991440 is a gapful number since it is divisible by the number (40) 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 45991440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (84262464).

45991440 is an abundant number, since it is smaller than the sum of its proper divisors (122533488).

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

45991440 is a wasteful number, since it uses less digits than its factorization.

45991440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5837 (or 5828 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 45991440 is about 6781.6989021926. The cubic root of 45991440 is about 358.2825604404.

It can be divided in two parts, 459914 and 40, that added together give a palindrome (459954).

The spelling of 45991440 in words is "forty-five million, nine hundred ninety-one thousand, four hundred forty".