405213321 has 4 divisors (see below), whose sum is σ = 540284432. Its totient is φ = 270142212.

The previous prime is 405213311. The next prime is 405213331. The reversal of 405213321 is 123312504.

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.

It is an interprime number because it is at equal distance from previous prime (405213311) and next prime (405213331).

It is not a de Polignac number, because 405213321 - 2⁹ = 405212809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (405213311) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 67535551 + ... + 67535556.

It is an arithmetic number, because the mean of its divisors is an integer number (135071108).

Almost surely, 2^405213321 is an apocalyptic number.

It is an amenable number.

405213321 is a deficient number, since it is larger than the sum of its proper divisors (135071111).

405213321 is a wasteful number, since it uses less digits than its factorization.

405213321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135071110.

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 405213321 is about 20129.9111026353. The cubic root of 405213321 is about 739.9934994559.

Adding to 405213321 its reverse (123312504), we get a palindrome (528525825).

The spelling of 405213321 in words is "four hundred five million, two hundred thirteen thousand, three hundred twenty-one".