2121213531 has 16 divisors (see below), whose sum is σ = 2861308800. Its totient is φ = 1397721408.

The previous prime is 2121213529. The next prime is 2121213551. The reversal of 2121213531 is 1353121212.

It is not a de Polignac number, because 2121213531 - 2¹ = 2121213529 is a prime.

It is a super-2 number, since 2×2121213531² = 8999093688194975922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 2121213498 and 2121213507.

It is not an unprimeable number, because it can be changed into a prime (2121213551) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 83455 + ... + 105863.

It is an arithmetic number, because the mean of its divisors is an integer number (178831800).

Almost surely, 2^2121213531 is an apocalyptic number.

2121213531 is a deficient number, since it is larger than the sum of its proper divisors (740095269).

2121213531 is a wasteful number, since it uses less digits than its factorization.

2121213531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22778.

The product of its digits is 360, while the sum is 21.

The square root of 2121213531 is about 46056.6339521246. The cubic root of 2121213531 is about 1284.8767273632.

Adding to 2121213531 its reverse (1353121212), we get a palindrome (3474334743).

It can be divided in two parts, 21212 and 13531, that added together give a palindrome (34743).

The spelling of 2121213531 in words is "two billion, one hundred twenty-one million, two hundred thirteen thousand, five hundred thirty-one".