15540216 has 16 divisors (see below), whose sum is σ = 38850600. Its totient is φ = 5180064.

The previous prime is 15540211. The next prime is 15540223. The reversal of 15540216 is 61204551.

It is a Harshad number since it is a multiple of its sum of digits (24), and also a Moran number because the ratio is a prime number: 647509 = 15540216 / (1 + 5 + 5 + 4 + 0 + 2 + 1 + 6).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15540211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 323731 + ... + 323778.

Almost surely, 2^15540216 is an apocalyptic number.

It is an amenable number.

15540216 is an abundant number, since it is smaller than the sum of its proper divisors (23310384).

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

15540216 is a wasteful number, since it uses less digits than its factorization.

15540216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 647518 (or 647514 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 15540216 is about 3942.1080654898. The cubic root of 15540216 is about 249.5469983204.

Adding to 15540216 its reverse (61204551), we get a palindrome (76744767).

The spelling of 15540216 in words is "fifteen million, five hundred forty thousand, two hundred sixteen".