55428990 has 64 divisors (see below), whose sum is σ = 137728512. Its totient is φ = 14268800.

The previous prime is 55428983. The next prime is 55428991. The reversal of 55428990 is 9982455.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55428991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 112645 + ... + 113135.

It is an arithmetic number, because the mean of its divisors is an integer number (2152008).

Almost surely, 2^55428990 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55428990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68864256).

55428990 is an abundant number, since it is smaller than the sum of its proper divisors (82299522).

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

55428990 is a wasteful number, since it uses less digits than its factorization.

55428990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 625.

The product of its (nonzero) digits is 129600, while the sum is 42.

The square root of 55428990 is about 7445.0648083143. The cubic root of 55428990 is about 381.2814310735.

The spelling of 55428990 in words is "fifty-five million, four hundred twenty-eight thousand, nine hundred ninety".