20261161800 has 480 divisors, whose sum is σ = 77958983520. Its totient is φ = 4835635200.

The previous prime is 20261161793. The next prime is 20261161801. The reversal of 20261161800 is 816116202.

20261161800 is a `hidden beast` number, since 20 + 26 + 1 + 1 + 618 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (20261161801) 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 119 ways as a sum of consecutive naturals, for example, 11938552 + ... + 11940248.

It is an arithmetic number, because the mean of its divisors is an integer number (162414549).

Almost surely, 2^20261161800 is an apocalyptic number.

20261161800 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 20261161800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38979491760).

20261161800 is an abundant number, since it is smaller than the sum of its proper divisors (57697821720).

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

20261161800 is a wasteful number, since it uses less digits than its factorization.

20261161800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1803 (or 1785 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The spelling of 20261161800 in words is "twenty billion, two hundred sixty-one million, one hundred sixty-one thousand, eight hundred".