400121678 has 8 divisors (see below), whose sum is σ = 654744600. Its totient is φ = 181873480.

The previous prime is 400121641. The next prime is 400121693. The reversal of 400121678 is 876121004.

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

It is a self number, because there is not a number n which added to its sum of digits gives 400121678.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 9093653 + ... + 9093696.

It is an arithmetic number, because the mean of its divisors is an integer number (81843075).

Almost surely, 2^400121678 is an apocalyptic number.

400121678 is a deficient number, since it is larger than the sum of its proper divisors (254622922).

400121678 is a wasteful number, since it uses less digits than its factorization.

400121678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18187362.

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 400121678 is about 20003.0417186987. The cubic root of 400121678 is about 736.8810030846.

The spelling of 400121678 in words is "four hundred million, one hundred twenty-one thousand, six hundred seventy-eight".