20506880 has 72 divisors (see below), whose sum is σ = 50564472. Its totient is φ = 7962624.

The previous prime is 20506877. The next prime is 20506897. The reversal of 20506880 is 8860502.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2119936 + 18386944 = 1456^2 + 4288^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47144 + ... + 47576.

Almost surely, 2^20506880 is an apocalyptic number.

20506880 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 20506880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25282236).

20506880 is an abundant number, since it is smaller than the sum of its proper divisors (30057592).

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

20506880 is an equidigital number, since it uses as much as digits as its factorization.

20506880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 491 (or 477 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 29.

The square root of 20506880 is about 4528.4522742323. The cubic root of 20506880 is about 273.7157974547.

The spelling of 20506880 in words is "twenty million, five hundred six thousand, eight hundred eighty".