213121020020 has 24 divisors (see below), whose sum is σ = 447605641224. Its totient is φ = 85238598656.

The previous prime is 213121020017. The next prime is 213121020037. The reversal of 213121020020 is 20020121312.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 36966214756 + 176154805264 = 192266^2 + 419708^2 .

It is a junction number, because it is equal to n+sod(n) for n = 213121019977 and 213121020004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 433649 + ... + 783768.

It is an arithmetic number, because the mean of its divisors is an integer number (18650235051).

Almost surely, 2^213121020020 is an apocalyptic number.

213121020020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

213121020020 is an abundant number, since it is smaller than the sum of its proper divisors (234484621204).

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

213121020020 is a wasteful number, since it uses less digits than its factorization.

213121020020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1226179 (or 1226177 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 213121020020 its reverse (20020121312), we get a palindrome (233141141332).

The spelling of 213121020020 in words is "two hundred thirteen billion, one hundred twenty-one million, twenty thousand, twenty".