405221042 has 4 divisors (see below), whose sum is σ = 607831566. Its totient is φ = 202610520.

The previous prime is 405221041. The next prime is 405221053. The reversal of 405221042 is 240122504.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 350475841 + 54745201 = 18721^2 + 7399^2 .

It is not an unprimeable number, because it can be changed into a prime (405221041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 101305259 + ... + 101305262.

Almost surely, 2^405221042 is an apocalyptic number.

405221042 is a deficient number, since it is larger than the sum of its proper divisors (202610524).

405221042 is a wasteful number, since it uses less digits than its factorization.

405221042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202610523.

The product of its (nonzero) digits is 640, while the sum is 20.

The square root of 405221042 is about 20130.1028810088. The cubic root of 405221042 is about 739.9981994113.

Adding to 405221042 its reverse (240122504), we get a palindrome (645343546).

The spelling of 405221042 in words is "four hundred five million, two hundred twenty-one thousand, forty-two".