20555340 has 144 divisors (see below), whose sum is σ = 66312288. Its totient is φ = 4727808.

The previous prime is 20555323. The next prime is 20555347. The reversal of 20555340 is 4355502.

It is a self number, because there is not a number n which added to its sum of digits gives 20555340.

It is not an unprimeable number, because it can be changed into a prime (20555347) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 281544 + ... + 281616.

It is an arithmetic number, because the mean of its divisors is an integer number (460502).

Almost surely, 2^20555340 is an apocalyptic number.

20555340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20555340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33156144).

20555340 is an abundant number, since it is smaller than the sum of its proper divisors (45756948).

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

20555340 is a wasteful number, since it uses less digits than its factorization.

20555340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136 (or 115 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 24.

The square root of 20555340 is about 4533.7997309100. The cubic root of 20555340 is about 273.9312346305.

The spelling of 20555340 in words is "twenty million, five hundred fifty-five thousand, three hundred forty".