15720240 has 80 divisors (see below), whose sum is σ = 51612768. Its totient is φ = 3944448.

The previous prime is 15720203. The next prime is 15720269. The reversal of 15720240 is 4202751.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2154 + ... + 6006.

Almost surely, 2^15720240 is an apocalyptic number.

15720240 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 15720240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25806384).

15720240 is an abundant number, since it is smaller than the sum of its proper divisors (35892528).

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

15720240 is a wasteful number, since it uses less digits than its factorization.

15720240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3886 (or 3880 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 15720240 is about 3964.8757862006. The cubic root of 15720240 is about 250.5069181081.

Adding to 15720240 its reverse (4202751), we get a palindrome (19922991).

The spelling of 15720240 in words is "fifteen million, seven hundred twenty thousand, two hundred forty".