43540640 has 144 divisors (see below), whose sum is σ = 122467464. Its totient is φ = 14530560.

The previous prime is 43540619. The next prime is 43540649. The reversal of 43540640 is 4604534.

It can be written as a sum of positive squares in 4 ways, for example, as 36336784 + 7203856 = 6028^2 + 2684^2 .

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43540649) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 251594 + ... + 251766.

Almost surely, 2^43540640 is an apocalyptic number.

43540640 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 43540640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (61233732).

43540640 is an abundant number, since it is smaller than the sum of its proper divisors (78926824).

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

43540640 is a wasteful number, since it uses less digits than its factorization.

43540640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223 (or 204 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 26.

The square root of 43540640 is about 6598.5331703341. The cubic root of 43540640 is about 351.8019719477.

The spelling of 43540640 in words is "forty-three million, five hundred forty thousand, six hundred forty".