21011220102120 has 32 divisors (see below), whose sum is σ = 63033660306720. Its totient is φ = 5602992027200.

The previous prime is 21011220102107. The next prime is 21011220102121. The reversal of 21011220102120 is 2120102211012.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21011220102120.

It is not an unprimeable number, because it can be changed into a prime (21011220102121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 87546750306 + ... + 87546750545.

It is an arithmetic number, because the mean of its divisors is an integer number (1969801884585).

Almost surely, 2^{21011220102120} is an apocalyptic number.

21011220102120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21011220102120 is an abundant number, since it is smaller than the sum of its proper divisors (42022440204600).

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

21011220102120 is a wasteful number, since it uses less digits than its factorization.

21011220102120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175093500865 (or 175093500861 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21011220102120 its reverse (2120102211012), we get a palindrome (23131322313132).

The spelling of 21011220102120 in words is "twenty-one trillion, eleven billion, two hundred twenty million, one hundred two thousand, one hundred twenty".