400012121 has 8 divisors (see below), whose sum is σ = 401681280. Its totient is φ = 398347488.

The previous prime is 400012103. The next prime is 400012163. The reversal of 400012121 is 121210004.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 400012121 - 2¹⁰ = 400011097 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (400012181) 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 7 ways as a sum of consecutive naturals, for example, 413180 + ... + 414146.

It is an arithmetic number, because the mean of its divisors is an integer number (50210160).

Almost surely, 2^400012121 is an apocalyptic number.

It is an amenable number.

400012121 is a deficient number, since it is larger than the sum of its proper divisors (1669159).

400012121 is an equidigital number, since it uses as much as digits as its factorization.

400012121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2263.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 400012121 is about 20000.3030227044. The cubic root of 400012121 is about 736.8137420105.

Adding to 400012121 its reverse (121210004), we get a palindrome (521222125).

The spelling of 400012121 in words is "four hundred million, twelve thousand, one hundred twenty-one".