55531440 has 160 divisors (see below), whose sum is σ = 195701760. Its totient is φ = 14466816.

The previous prime is 55531429. The next prime is 55531457. The reversal of 55531440 is 4413555.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 101247 + ... + 101793.

It is an arithmetic number, because the mean of its divisors is an integer number (1223136).

Almost surely, 2^55531440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55531440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97850880).

55531440 is an abundant number, since it is smaller than the sum of its proper divisors (140170320).

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

55531440 is a wasteful number, since it uses less digits than its factorization.

55531440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 616 (or 604 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 27.

The square root of 55531440 is about 7451.9420287600. The cubic root of 55531440 is about 381.5161953541.

Adding to 55531440 its reverse (4413555), we get a palindrome (59944995).

The spelling of 55531440 in words is "fifty-five million, five hundred thirty-one thousand, four hundred forty".