55009920 has 128 divisors (see below), whose sum is σ = 200442240. Its totient is φ = 12570624.

The previous prime is 55009901. The next prime is 55009939. The reversal of 55009920 is 2990055.

It is an interprime number because it is at equal distance from previous prime (55009901) and next prime (55009939).

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11394 + ... + 15486.

It is an arithmetic number, because the mean of its divisors is an integer number (1565955).

Almost surely, 2^55009920 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 55009920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100221120).

55009920 is an abundant number, since it is smaller than the sum of its proper divisors (145432320).

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

55009920 is a wasteful number, since it uses less digits than its factorization.

55009920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4122 (or 4110 counting only the distinct ones).

The product of its (nonzero) digits is 4050, while the sum is 30.

The square root of 55009920 is about 7416.8672632049. The cubic root of 55009920 is about 380.3181085128.

Adding to 55009920 its reverse (2990055), we get a palindrome (57999975).

The spelling of 55009920 in words is "fifty-five million, nine thousand, nine hundred twenty".