15781461678887 has 2 divisors, whose sum is σ = 15781461678888. Its totient is φ = 15781461678886.

The previous prime is 15781461678881. The next prime is 15781461678919. The reversal of 15781461678887 is 78887616418751.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 15781461678887 - 2³⁶ = 15712742202151 is a prime.

It is a super-3 number, since 3×15781461678887³ (a number of 41 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15781461678881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7890730839443 + 7890730839444.

It is an arithmetic number, because the mean of its divisors is an integer number (7890730839444).

Almost surely, 2^{15781461678887} is an apocalyptic number.

15781461678887 is a deficient number, since it is larger than the sum of its proper divisors (1).

15781461678887 is an equidigital number, since it uses as much as digits as its factorization.

15781461678887 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1011548160, while the sum is 77.

The spelling of 15781461678887 in words is "fifteen trillion, seven hundred eighty-one billion, four hundred sixty-one million, six hundred seventy-eight thousand, eight hundred eighty-seven".