55420040 has 64 divisors (see below), whose sum is σ = 135218160. Its totient is φ = 20321280.

The previous prime is 55420039. The next prime is 55420049. The reversal of 55420040 is 4002455.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 27899524 + 27520516 = 5282^2 + 5246^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 55419994 and 55420021.

It is not an unprimeable number, because it can be changed into a prime (55420049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 102170 + ... + 102710.

Almost surely, 2^55420040 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 55420040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (67609080).

55420040 is an abundant number, since it is smaller than the sum of its proper divisors (79798120).

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

55420040 is a wasteful number, since it uses less digits than its factorization.

55420040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 762 (or 758 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 20.

The square root of 55420040 is about 7444.4637147346. The cubic root of 55420040 is about 381.2609084042.

Adding to 55420040 its reverse (4002455), we get a palindrome (59422495).

The spelling of 55420040 in words is "fifty-five million, four hundred twenty thousand, forty".