15120840 has 128 divisors (see below), whose sum is σ = 53084160. Its totient is φ = 3373824.

The previous prime is 15120823. The next prime is 15120877. The reversal of 15120840 is 4802151.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 39289 + ... + 39671.

It is an arithmetic number, because the mean of its divisors is an integer number (414720).

Almost surely, 2^15120840 is an apocalyptic number.

15120840 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 15120840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26542080).

15120840 is an abundant number, since it is smaller than the sum of its proper divisors (37963320).

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

15120840 is a wasteful number, since it uses less digits than its factorization.

15120840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 451 (or 447 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 21.

The square root of 15120840 is about 3888.5524298896. The cubic root of 15120840 is about 247.2816971096.

Adding to 15120840 its reverse (4802151), we get a palindrome (19922991).

The spelling of 15120840 in words is "fifteen million, one hundred twenty thousand, eight hundred forty".