20861018280 has 96 divisors (see below), whose sum is σ = 69375065760. Its totient is φ = 5433563520.

The previous prime is 20861018267. The next prime is 20861018287. The reversal of 20861018280 is 8281016802.

20861018280 is a `hidden beast` number, since 2 + 0 + 8 + 610 + 18 + 28 + 0 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (20861018287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 658326 + ... + 689285.

It is an arithmetic number, because the mean of its divisors is an integer number (722656935).

Almost surely, 2^20861018280 is an apocalyptic number.

20861018280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20861018280 is an abundant number, since it is smaller than the sum of its proper divisors (48514047480).

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

20861018280 is a wasteful number, since it uses less digits than its factorization.

20861018280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1347671 (or 1347664 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 36.

The spelling of 20861018280 in words is "twenty billion, eight hundred sixty-one million, eighteen thousand, two hundred eighty".