55320440 has 32 divisors (see below), whose sum is σ = 142253280. Its totient is φ = 18966912.

The previous prime is 55320437. The next prime is 55320467. The reversal of 55320440 is 4402355.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 98507 + ... + 99066.

It is an arithmetic number, because the mean of its divisors is an integer number (4445415).

Almost surely, 2^55320440 is an apocalyptic number.

It is an amenable number.

55320440 is an abundant number, since it is smaller than the sum of its proper divisors (86932840).

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

55320440 is a wasteful number, since it uses less digits than its factorization.

55320440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197591 (or 197587 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 23.

The square root of 55320440 is about 7437.7711715271. The cubic root of 55320440 is about 381.0323727955.

Adding to 55320440 its reverse (4402355), we get a palindrome (59722795).

The spelling of 55320440 in words is "fifty-five million, three hundred twenty thousand, four hundred forty".