400123221 has 4 divisors (see below), whose sum is σ = 533497632. Its totient is φ = 266748812.

The previous prime is 400123219. The next prime is 400123277. The reversal of 400123221 is 122321004.

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 400123221 - 2¹ = 400123219 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 400123221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400123201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66687201 + ... + 66687206.

It is an arithmetic number, because the mean of its divisors is an integer number (133374408).

Almost surely, 2^400123221 is an apocalyptic number.

It is an amenable number.

400123221 is a deficient number, since it is larger than the sum of its proper divisors (133374411).

400123221 is a wasteful number, since it uses less digits than its factorization.

400123221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133374410.

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 400123221 is about 20003.0802877957. The cubic root of 400123221 is about 736.8819503014.

Adding to 400123221 its reverse (122321004), we get a palindrome (522444225).

The spelling of 400123221 in words is "four hundred million, one hundred twenty-three thousand, two hundred twenty-one".