531387440 has 80 divisors (see below), whose sum is σ = 1318591200. Its totient is φ = 198567936.

The previous prime is 531387419. The next prime is 531387443. The reversal of 531387440 is 44783135.

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

It is a super-2 number, since 2×531387440² = 564745222779507200, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 531387440.

It is not an unprimeable number, because it can be changed into a prime (531387443) 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, 108566 + ... + 113354.

It is an arithmetic number, because the mean of its divisors is an integer number (16482390).

Almost surely, 2^531387440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 531387440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (659295600).

531387440 is an abundant number, since it is smaller than the sum of its proper divisors (787203760).

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

531387440 is a wasteful number, since it uses less digits than its factorization.

531387440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4894 (or 4888 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 35.

The square root of 531387440 is about 23051.8424426335. The cubic root of 531387440 is about 809.9727877867.

The spelling of 531387440 in words is "five hundred thirty-one million, three hundred eighty-seven thousand, four hundred forty".