15665991540 has 48 divisors (see below), whose sum is σ = 43923938688. Its totient is φ = 4171963264.

The previous prime is 15665991503. The next prime is 15665991547. The reversal of 15665991540 is 4519956651.

15665991540 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15665991547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 131127 + ... + 220286.

It is an arithmetic number, because the mean of its divisors is an integer number (915082056).

Almost surely, 2^15665991540 is an apocalyptic number.

15665991540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

15665991540 is an abundant number, since it is smaller than the sum of its proper divisors (28257947148).

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

15665991540 is a wasteful number, since it uses less digits than its factorization.

15665991540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 352168 (or 352166 counting only the distinct ones).

The product of its (nonzero) digits is 1458000, while the sum is 51.

The spelling of 15665991540 in words is "fifteen billion, six hundred sixty-five million, nine hundred ninety-one thousand, five hundred forty".