400121000 has 64 divisors (see below), whose sum is σ = 985608000. Its totient is φ = 151617600.

The previous prime is 400120991. The next prime is 400121003. The reversal of 400121000 is 121004.

It is a Harshad number since it is a multiple of its sum of digits (8).

It is not an unprimeable number, because it can be changed into a prime (400121003) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8471 + ... + 29529.

It is an arithmetic number, because the mean of its divisors is an integer number (15400125).

Almost surely, 2^400121000 is an apocalyptic number.

400121000 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 400121000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (492804000).

400121000 is an abundant number, since it is smaller than the sum of its proper divisors (585487000).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

400121000 is a wasteful number, since it uses less digits than its factorization.

400121000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21099 (or 21085 counting only the distinct ones).

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

The square root of 400121000 is about 20003.0247712690. The cubic root of 400121000 is about 736.8805868732.

Adding to 400121000 its reverse (121004), we get a palindrome (400242004).

The spelling of 400121000 in words is "four hundred million, one hundred twenty-one thousand".