400002121 has 8 divisors (see below), whose sum is σ = 404167680. Its totient is φ = 395852688.

The previous prime is 400002089. The next prime is 400002151. The reversal of 400002121 is 121200004.

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 400002121 - 2⁵ = 400002089 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 400002098 and 400002107.

It is not an unprimeable number, because it can be changed into a prime (400002151) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49455 + ... + 56971.

It is an arithmetic number, because the mean of its divisors is an integer number (50520960).

Almost surely, 2^400002121 is an apocalyptic number.

It is an amenable number.

400002121 is a deficient number, since it is larger than the sum of its proper divisors (4165559).

400002121 is a wasteful number, since it uses less digits than its factorization.

400002121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8063.

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 400002121 is about 20000.0530249297. The cubic root of 400002121 is about 736.8076020309.

Adding to 400002121 its reverse (121200004), we get a palindrome (521202125).

The spelling of 400002121 in words is "four hundred million, two thousand, one hundred twenty-one".