21155013330100 has 36 divisors (see below), whose sum is σ = 49437638846764. Its totient is φ = 7811081844480.

The previous prime is 21155013330083. The next prime is 21155013330109. The reversal of 21155013330100 is 103331055112.

It can be written as a sum of positive squares in 6 ways, for example, as 106040107044 + 21048973223056 = 325638^2 + 4587916^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21155013330109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8136542289 + ... + 8136544888.

Almost surely, 2^{21155013330100} is an apocalyptic number.

21155013330100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21155013330100 is an abundant number, since it is smaller than the sum of its proper divisors (28282625516664).

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

21155013330100 is a wasteful number, since it uses less digits than its factorization.

21155013330100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16273087204 (or 16273087197 counting only the distinct ones).

The product of its (nonzero) digits is 1350, while the sum is 25.

Adding to 21155013330100 its reverse (103331055112), we get a palindrome (21258344385212).

The spelling of 21155013330100 in words is "twenty-one trillion, one hundred fifty-five billion, thirteen million, three hundred thirty thousand, one hundred".