15663540987 has 12 divisors (see below), whose sum is σ = 23405291520. Its totient is φ = 10082279088.

The previous prime is 15663540979. The next prime is 15663541001. The reversal of 15663540987 is 78904536651.

15663540987 is a `hidden beast` number, since 1 + 5 + 6 + 6 + 3 + 540 + 98 + 7 = 666.

It is not a de Polignac number, because 15663540987 - 2³ = 15663540979 is a prime.

It is not an unprimeable number, because it can be changed into a prime (15663540947) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 30006523 + ... + 30007044.

It is an arithmetic number, because the mean of its divisors is an integer number (1950440960).

Almost surely, 2^15663540987 is an apocalyptic number.

15663540987 is a deficient number, since it is larger than the sum of its proper divisors (7741750533).

15663540987 is a wasteful number, since it uses less digits than its factorization.

15663540987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60013602 (or 60013599 counting only the distinct ones).

The product of its (nonzero) digits is 5443200, while the sum is 54.

The spelling of 15663540987 in words is "fifteen billion, six hundred sixty-three million, five hundred forty thousand, nine hundred eighty-seven".