21518150800 has 60 divisors (see below), whose sum is σ = 53480053620. Its totient is φ = 8310453760.

The previous prime is 21518150747. The next prime is 21518150803. The reversal of 21518150800 is 805181512.

It can be written as a sum of positive squares in 6 ways, for example, as 781456 + 21517369344 = 884^2 + 146688^2 .

It is not an unprimeable number, because it can be changed into a prime (21518150803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 915907 + ... + 939106.

It is an arithmetic number, because the mean of its divisors is an integer number (891334227).

Almost surely, 2^21518150800 is an apocalyptic number.

21518150800 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21518150800 is an abundant number, since it is smaller than the sum of its proper divisors (31961902820).

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

21518150800 is a wasteful number, since it uses less digits than its factorization.

21518150800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1855060 (or 1855049 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 31.

The spelling of 21518150800 in words is "twenty-one billion, five hundred eighteen million, one hundred fifty thousand, eight hundred".