20755980 has 288 divisors, whose sum is σ = 82521600. Its totient is φ = 4230144.

The previous prime is 20755951. The next prime is 20755981. The reversal of 20755980 is 8955702.

20755980 is a `hidden beast` number, since 20 + 7 + 559 + 80 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20755981) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1092411 + ... + 1092429.

Almost surely, 2^20755980 is an apocalyptic number.

20755980 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 20755980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41260800).

20755980 is an abundant number, since it is smaller than the sum of its proper divisors (61765620).

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

20755980 is a wasteful number, since it uses less digits than its factorization.

20755980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78 (or 53 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 36.

The square root of 20755980 is about 4555.8731325620. The cubic root of 20755980 is about 274.8196282770.

The spelling of 20755980 in words is "twenty million, seven hundred fifty-five thousand, nine hundred eighty".