402231440 has 80 divisors (see below), whose sum is σ = 1034444208. Its totient is φ = 144488448.

The previous prime is 402231419. The next prime is 402231451. The reversal of 402231440 is 44132204.

It can be written as a sum of positive squares in 8 ways, for example, as 31899904 + 370331536 = 5648^2 + 19244^2 .

It is a tau number, because it is divible by the number of its divisors (80).

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

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33254 + ... + 43706.

Almost surely, 2^402231440 is an apocalyptic number.

402231440 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 402231440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (517222104).

402231440 is an abundant number, since it is smaller than the sum of its proper divisors (632212768).

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

402231440 is a wasteful number, since it uses less digits than its factorization.

402231440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10516 (or 10510 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 402231440 is about 20055.7084143144. The cubic root of 402231440 is about 738.1738756934.

Adding to 402231440 its reverse (44132204), we get a palindrome (446363644).

The spelling of 402231440 in words is "four hundred two million, two hundred thirty-one thousand, four hundred forty".