400010121 has 24 divisors (see below), whose sum is σ = 661175424. Its totient is φ = 228286080.

The previous prime is 400010111. The next prime is 400010129. The reversal of 400010121 is 121010004.

It is a happy number.

It is not a de Polignac number, because 400010121 - 2⁶ = 400010057 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (400010129) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 51900 + ... + 59106.

It is an arithmetic number, because the mean of its divisors is an integer number (27548976).

Almost surely, 2^400010121 is an apocalyptic number.

It is an amenable number.

400010121 is a deficient number, since it is larger than the sum of its proper divisors (261165303).

400010121 is a wasteful number, since it uses less digits than its factorization.

400010121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8101 (or 8098 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 400010121 is about 20000.2530233995. The cubic root of 400010121 is about 736.8125140228.

Adding to 400010121 its reverse (121010004), we get a palindrome (521020125).

The spelling of 400010121 in words is "four hundred million, ten thousand, one hundred twenty-one".