20281880 has 64 divisors (see below), whose sum is σ = 47628000. Its totient is φ = 7767040.

The previous prime is 20281879. The next prime is 20281889. The reversal of 20281880 is 8818202.

20281880 = T₄₀₉ + T₄₁₀ + ... + T₅₇₄.

It is a super-2 number, since 2×20281880² = 822709312668800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20281889) 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, 136046 + ... + 136194.

Almost surely, 2^20281880 is an apocalyptic number.

20281880 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 20281880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23814000).

20281880 is an abundant number, since it is smaller than the sum of its proper divisors (27346120).

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

20281880 is a wasteful number, since it uses less digits than its factorization.

20281880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284 (or 280 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 29.

The square root of 20281880 is about 4503.5408291699. The cubic root of 20281880 is about 272.7110504829.

The spelling of 20281880 in words is "twenty million, two hundred eighty-one thousand, eight hundred eighty".