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15978240 = 283251973

15978240 has 216 divisors, whose sum is σ = 58989840. Its totient is φ = 3981312.

The previous prime is 15978239. The next prime is 15978253. The reversal of 15978240 is 4287951.

15978240 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 15978195 and 15978204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 218844 + ... + 218916.

Almost surely, 215978240 is an apocalyptic number.

15978240 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 15978240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29494920).

15978240 is an abundant number, since it is smaller than the sum of its proper divisors (43011600).

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

15978240 is a wasteful number, since it uses less digits than its factorization.

15978240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119 (or 102 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 15978240 is about 3997.2790745706. The cubic root of 15978240 is about 251.8699253124.

The spelling of 15978240 in words is "fifteen million, nine hundred seventy-eight thousand, two hundred forty".