40215540 has 96 divisors (see below), whose sum is σ = 120839040. Its totient is φ = 9957376.

The previous prime is 40215529. The next prime is 40215563. The reversal of 40215540 is 4551204.

It is a nialpdrome in base 7.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 90559 + ... + 91001.

It is an arithmetic number, because the mean of its divisors is an integer number (1258740).

Almost surely, 2^40215540 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 40215540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (60419520).

40215540 is an abundant number, since it is smaller than the sum of its proper divisors (80623500).

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

40215540 is a wasteful number, since it uses less digits than its factorization.

40215540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 561 (or 559 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 21.

The square root of 40215540 is about 6341.5723602274. The cubic root of 40215540 is about 342.6083696359.

Adding to 40215540 its reverse (4551204), we get a palindrome (44766744).

It can be divided in two parts, 40215 and 540, that added together give a triangular number (40755 = T₂₈₅).

The spelling of 40215540 in words is "forty million, two hundred fifteen thousand, five hundred forty".