213121202420 has 96 divisors (see below), whose sum is σ = 533812204800. Its totient is φ = 69925976064.

The previous prime is 213121202417. The next prime is 213121202431. The reversal of 213121202420 is 24202121312.

It is a super-2 number, since 2×213121202420² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 213121202392 and 213121202401.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 226511 + ... + 691049.

It is an arithmetic number, because the mean of its divisors is an integer number (5560543800).

Almost surely, 2^213121202420 is an apocalyptic number.

213121202420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 213121202420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (266906102400).

213121202420 is an abundant number, since it is smaller than the sum of its proper divisors (320691002380).

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

213121202420 is a wasteful number, since it uses less digits than its factorization.

213121202420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 464697 (or 464695 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 213121202420 its reverse (24202121312), we get a palindrome (237323323732).

The spelling of 213121202420 in words is "two hundred thirteen billion, one hundred twenty-one million, two hundred two thousand, four hundred twenty".