15978695040 has 640 divisors, whose sum is σ = 71161009920. Its totient is φ = 3319418880.

The previous prime is 15978695017. The next prime is 15978695041. The reversal of 15978695040 is 4059687951.

15978695040 is a `hidden beast` number, since 1 + 5 + 9 + 78 + 69 + 504 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (640).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15978695041) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 3989679 + ... + 3993681.

It is an arithmetic number, because the mean of its divisors is an integer number (111189078).

Almost surely, 2^15978695040 is an apocalyptic number.

15978695040 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 15978695040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35580504960).

15978695040 is an abundant number, since it is smaller than the sum of its proper divisors (55182314880).

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

15978695040 is a wasteful number, since it uses less digits than its factorization.

15978695040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4052 (or 4031 counting only the distinct ones).

The product of its (nonzero) digits is 2721600, while the sum is 54.

The spelling of 15978695040 in words is "fifteen billion, nine hundred seventy-eight million, six hundred ninety-five thousand, forty".