100515211220 has 12 divisors (see below), whose sum is σ = 211081943604. Its totient is φ = 40206084480.

The previous prime is 100515211169. The next prime is 100515211231. The reversal of 100515211220 is 22112515001.

It can be written as a sum of positive squares in 2 ways, for example, as 24023140036 + 76492071184 = 154994^2 + 276572^2 .

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 5025760561 = 100515211220 / (1 + 0 + 0 + 5 + 1 + 5 + 2 + 1 + 1 + 2 + 2 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 100515211192 and 100515211201.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2512880261 + ... + 2512880300.

It is an arithmetic number, because the mean of its divisors is an integer number (17590161967).

Almost surely, 2^100515211220 is an apocalyptic number.

100515211220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

100515211220 is an abundant number, since it is smaller than the sum of its proper divisors (110566732384).

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

100515211220 is a wasteful number, since it uses less digits than its factorization.

100515211220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5025760570 (or 5025760568 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 20.

Adding to 100515211220 its reverse (22112515001), we get a palindrome (122627726221).

The spelling of 100515211220 in words is "one hundred billion, five hundred fifteen million, two hundred eleven thousand, two hundred twenty".