400125440 has 160 divisors (see below), whose sum is σ = 1128115296. Its totient is φ = 134184960.

The previous prime is 400125421. The next prime is 400125443. The reversal of 400125440 is 44521004.

It is a tau number, because it is divible by the number of its divisors (160).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400125443) 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, 365534 + ... + 366626.

Almost surely, 2^400125440 is an apocalyptic number.

400125440 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 400125440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (564057648).

400125440 is an abundant number, since it is smaller than the sum of its proper divisors (727989856).

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

400125440 is a wasteful number, since it uses less digits than its factorization.

400125440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1140 (or 1124 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 20.

The square root of 400125440 is about 20003.1357541761. The cubic root of 400125440 is about 736.8833124968.

Adding to 400125440 its reverse (44521004), we get a palindrome (444646444).

The spelling of 400125440 in words is "four hundred million, one hundred twenty-five thousand, four hundred forty".