53991144 has 64 divisors (see below), whose sum is σ = 153489600. Its totient is φ = 17575488.

The previous prime is 53991139. The next prime is 53991149. The reversal of 53991144 is 44119935.

It is a happy number.

53991144 is a `hidden beast` number, since 539 + 9 + 114 + 4 = 666.

It is an interprime number because it is at equal distance from previous prime (53991139) and next prime (53991149).

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 = 53991099 and 53991108.

It is not an unprimeable number, because it can be changed into a prime (53991149) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6382 + ... + 12194.

It is an arithmetic number, because the mean of its divisors is an integer number (2398275).

Almost surely, 2^53991144 is an apocalyptic number.

53991144 is a gapful number since it is divisible by the number (54) 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 53991144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76744800).

53991144 is an abundant number, since it is smaller than the sum of its proper divisors (99498456).

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

53991144 is a wasteful number, since it uses less digits than its factorization.

53991144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5871 (or 5861 counting only the distinct ones).

The product of its digits is 19440, while the sum is 36.

The square root of 53991144 is about 7347.8666291652. The cubic root of 53991144 is about 377.9556511336.

The spelling of 53991144 in words is "fifty-three million, nine hundred ninety-one thousand, one hundred forty-four".