400340221 has 4 divisors (see below), whose sum is σ = 400494112. Its totient is φ = 400186332.

The previous prime is 400340201. The next prime is 400340261. The reversal of 400340221 is 122043004.

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 400340221 - 2⁵ = 400340189 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 400340195 and 400340204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400340201) 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, 72975 + ... + 78268.

It is an arithmetic number, because the mean of its divisors is an integer number (100123528).

Almost surely, 2^400340221 is an apocalyptic number.

It is an amenable number.

400340221 is a deficient number, since it is larger than the sum of its proper divisors (153891).

400340221 is a wasteful number, since it uses less digits than its factorization.

400340221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153890.

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 400340221 is about 20008.5037171699. The cubic root of 400340221 is about 737.0151380100.

Adding to 400340221 its reverse (122043004), we get a palindrome (522383225).

The spelling of 400340221 in words is "four hundred million, three hundred forty thousand, two hundred twenty-one".