400240221 has 4 divisors (see below), whose sum is σ = 533653632. Its totient is φ = 266826812.

The previous prime is 400240219. The next prime is 400240249. The reversal of 400240221 is 122042004.

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 a cyclic number.

It is not a de Polignac number, because 400240221 - 2¹ = 400240219 is a prime.

It is a super-2 number, since 2×400240221² = 320384469012257682, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 400240221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400240021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66706701 + ... + 66706706.

It is an arithmetic number, because the mean of its divisors is an integer number (133413408).

Almost surely, 2^400240221 is an apocalyptic number.

It is an amenable number.

400240221 is a deficient number, since it is larger than the sum of its proper divisors (133413411).

400240221 is a wasteful number, since it uses less digits than its factorization.

400240221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133413410.

The product of its (nonzero) digits is 128, while the sum is 15.

The square root of 400240221 is about 20006.0046236124. The cubic root of 400240221 is about 736.9537671665.

Adding to 400240221 its reverse (122042004), we get a palindrome (522282225).

The spelling of 400240221 in words is "four hundred million, two hundred forty thousand, two hundred twenty-one".