15780240 has 240 divisors, whose sum is σ = 63138816. Its totient is φ = 3456000.

The previous prime is 15780239. The next prime is 15780283. The reversal of 15780240 is 4208751.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 156190 + ... + 156290.

Almost surely, 2^15780240 is an apocalyptic number.

15780240 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 15780240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31569408).

15780240 is an abundant number, since it is smaller than the sum of its proper divisors (47358576).

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

15780240 is a wasteful number, since it uses less digits than its factorization.

15780240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158 (or 149 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 15780240 is about 3972.4350214950. The cubic root of 15780240 is about 250.8252197192.

Adding to 15780240 its reverse (4208751), we get a palindrome (19988991).

The spelling of 15780240 in words is "fifteen million, seven hundred eighty thousand, two hundred forty".