15871645440 has 720 divisors, whose sum is σ = 68380139520. Its totient is φ = 3433881600.

The previous prime is 15871645429. The next prime is 15871645441. The reversal of 15871645440 is 4454617851.

15871645440 is a `hidden beast` number, since 1 + 587 + 1 + 64 + 5 + 4 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15871645441) 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, 13788865 + ... + 13790015.

It is an arithmetic number, because the mean of its divisors is an integer number (94972416).

Almost surely, 2^15871645440 is an apocalyptic number.

15871645440 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 15871645440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34190069760).

15871645440 is an abundant number, since it is smaller than the sum of its proper divisors (52508494080).

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

15871645440 is a wasteful number, since it uses less digits than its factorization.

15871645440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1210 (or 1187 counting only the distinct ones).

The product of its (nonzero) digits is 537600, while the sum is 45.

The spelling of 15871645440 in words is "fifteen billion, eight hundred seventy-one million, six hundred forty-five thousand, four hundred forty".