2121012121020 has 72 divisors (see below), whose sum is σ = 6430808378736. Its totient is φ = 522095288832.

The previous prime is 2121012120989. The next prime is 2121012121027. The reversal of 2121012121020 is 201212101212.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121012121027) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 104576257 + ... + 104596536.

It is an arithmetic number, because the mean of its divisors is an integer number (89316783038).

Almost surely, 2^{2121012121020} is an apocalyptic number.

2121012121020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2121012121020 is an abundant number, since it is smaller than the sum of its proper divisors (4309796257716).

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

2121012121020 is a wasteful number, since it uses less digits than its factorization.

2121012121020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209172831 (or 209172816 counting only the distinct ones).

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

Adding to 2121012121020 its reverse (201212101212), we get a palindrome (2322224222232).

The spelling of 2121012121020 in words is "two trillion, one hundred twenty-one billion, twelve million, one hundred twenty-one thousand, twenty".