15864240 has 240 divisors, whose sum is σ = 61067520. Its totient is φ = 3386880.

The previous prime is 15864229. The next prime is 15864241. The reversal of 15864240 is 4246851.

It is a tau number, because it is divible by the number of its divisors (240).

It is a super-2 number, since 2×15864240² = 503348221555200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 15864198 and 15864207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15864241) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 223405 + ... + 223475.

It is an arithmetic number, because the mean of its divisors is an integer number (254448).

Almost surely, 2^15864240 is an apocalyptic number.

15864240 is a gapful number since it is divisible by the number (10) 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 15864240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30533760).

15864240 is an abundant number, since it is smaller than the sum of its proper divisors (45203280).

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

15864240 is a wasteful number, since it uses less digits than its factorization.

15864240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120 (or 107 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 30.

The square root of 15864240 is about 3982.9938488529. The cubic root of 15864240 is about 251.2694893424.

The spelling of 15864240 in words is "fifteen million, eight hundred sixty-four thousand, two hundred forty".