20155620 has 48 divisors (see below), whose sum is σ = 57371328. Its totient is φ = 5285760.

The previous prime is 20155607. The next prime is 20155627. The reversal of 20155620 is 2655102.

It is not an unprimeable number, because it can be changed into a prime (20155627) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 907 + ... + 6413.

It is an arithmetic number, because the mean of its divisors is an integer number (1195236).

Almost surely, 2^20155620 is an apocalyptic number.

20155620 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 20155620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28685664).

20155620 is an abundant number, since it is smaller than the sum of its proper divisors (37215708).

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

20155620 is a wasteful number, since it uses less digits than its factorization.

20155620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5580 (or 5578 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 20155620 is about 4489.5010858669. The cubic root of 20155620 is about 272.1439729437.

The spelling of 20155620 in words is "twenty million, one hundred fifty-five thousand, six hundred twenty".