400340121 has 4 divisors (see below), whose sum is σ = 533786832. Its totient is φ = 266893412.

The previous prime is 400340119. The next prime is 400340131. The reversal of 400340121 is 121043004.

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 400340121 - 2¹ = 400340119 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 400340121.

It is not an unprimeable number, because it can be changed into a prime (400340131) 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, 66723351 + ... + 66723356.

It is an arithmetic number, because the mean of its divisors is an integer number (133446708).

Almost surely, 2^400340121 is an apocalyptic number.

It is an amenable number.

400340121 is a deficient number, since it is larger than the sum of its proper divisors (133446711).

400340121 is a wasteful number, since it uses less digits than its factorization.

400340121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133446710.

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

The square root of 400340121 is about 20008.5012182322. The cubic root of 400340121 is about 737.0150766443.

Adding to 400340121 its reverse (121043004), we get a palindrome (521383125).

The spelling of 400340121 in words is "four hundred million, three hundred forty thousand, one hundred twenty-one".