400002020122121 has 4 divisors (see below), whose sum is σ = 400021698502272. Its totient is φ = 399982341741972.

The previous prime is 400002020122109. The next prime is 400002020122163. The reversal of 400002020122121 is 121221020200004.

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 400002020122121 - 2⁶ = 400002020122057 is a prime.

It is a super-2 number, since 2×400002020122121² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 400002020122121.

It is not an unprimeable number, because it can be changed into a prime (400002020122321) 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, 9839159585 + ... + 9839200238.

It is an arithmetic number, because the mean of its divisors is an integer number (100005424625568).

Almost surely, 2^{400002020122121} is an apocalyptic number.

It is an amenable number.

400002020122121 is a deficient number, since it is larger than the sum of its proper divisors (19678380151).

400002020122121 is a wasteful number, since it uses less digits than its factorization.

400002020122121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19678380150.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 400002020122121 its reverse (121221020200004), we get a palindrome (521223040322125).

The spelling of 400002020122121 in words is "four hundred trillion, two billion, twenty million, one hundred twenty-two thousand, one hundred twenty-one".