400121440 has 24 divisors (see below), whose sum is σ = 945287280. Its totient is φ = 160048512.

The previous prime is 400121431. The next prime is 400121467. The reversal of 400121440 is 44121004.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1250220 + ... + 1250539.

It is an arithmetic number, because the mean of its divisors is an integer number (39386970).

Almost surely, 2^400121440 is an apocalyptic number.

400121440 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

400121440 is an abundant number, since it is smaller than the sum of its proper divisors (545165840).

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

400121440 is a wasteful number, since it uses less digits than its factorization.

400121440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2500774 (or 2500766 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 400121440 is about 20003.0357696026. The cubic root of 400121440 is about 736.8808569809.

Adding to 400121440 its reverse (44121004), we get a palindrome (444242444).

The spelling of 400121440 in words is "four hundred million, one hundred twenty-one thousand, four hundred forty".