213532021 has 4 divisors (see below), whose sum is σ = 213563200. Its totient is φ = 213500844.

The previous prime is 213531991. The next prime is 213532027. The reversal of 213532021 is 120235312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 213532021 - 2¹¹ = 213529973 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 213532021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213532027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 351 + ... + 20668.

It is an arithmetic number, because the mean of its divisors is an integer number (53390800).

Almost surely, 2^213532021 is an apocalyptic number.

It is an amenable number.

213532021 is a deficient number, since it is larger than the sum of its proper divisors (31179).

213532021 is a wasteful number, since it uses less digits than its factorization.

213532021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31178.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 213532021 is about 14612.7348911831. The cubic root of 213532021 is about 597.7060752850.

Adding to 213532021 its reverse (120235312), we get a palindrome (333767333).

The spelling of 213532021 in words is "two hundred thirteen million, five hundred thirty-two thousand, twenty-one".