405801221 has 16 divisors (see below), whose sum is σ = 490742400. Its totient is φ = 327794688.

The previous prime is 405801217. The next prime is 405801257. The reversal of 405801221 is 122108504.

It is not a de Polignac number, because 405801221 - 2² = 405801217 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405801821) 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, 17765 + ... + 33573.

It is an arithmetic number, because the mean of its divisors is an integer number (30671400).

Almost surely, 2^405801221 is an apocalyptic number.

It is an amenable number.

405801221 is a deficient number, since it is larger than the sum of its proper divisors (84941179).

405801221 is a wasteful number, since it uses less digits than its factorization.

405801221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16028.

The product of its (nonzero) digits is 640, while the sum is 23.

The square root of 405801221 is about 20144.5084576418. The cubic root of 405801221 is about 740.3511974329.

Adding to 405801221 its reverse (122108504), we get a palindrome (527909725).

The spelling of 405801221 in words is "four hundred five million, eight hundred one thousand, two hundred twenty-one".