400421121 has 16 divisors (see below), whose sum is σ = 538843200. Its totient is φ = 264483648.

The previous prime is 400421113. The next prime is 400421123. The reversal of 400421121 is 121124004.

It is not a de Polignac number, because 400421121 - 2³ = 400421113 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 400421121.

It is not an unprimeable number, because it can be changed into a prime (400421123) 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, 196335 + ... + 198363.

It is an arithmetic number, because the mean of its divisors is an integer number (33677700).

Almost surely, 2^400421121 is an apocalyptic number.

It is an amenable number.

400421121 is a deficient number, since it is larger than the sum of its proper divisors (138422079).

400421121 is a wasteful number, since it uses less digits than its factorization.

400421121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2608.

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 400421121 is about 20010.5252554749. The cubic root of 400421121 is about 737.0647795447.

Adding to 400421121 its reverse (121124004), we get a palindrome (521545125).

The spelling of 400421121 in words is "four hundred million, four hundred twenty-one thousand, one hundred twenty-one".