161287931087 has 4 divisors (see below), whose sum is σ = 161412864936. Its totient is φ = 161162997240.

The previous prime is 161287931047. The next prime is 161287931141. The reversal of 161287931087 is 780139782161.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 161287931087 - 2³⁶ = 92568454351 is a prime.

It is a super-2 number, since 2×161287931087² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161287931017) 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 3 ways as a sum of consecutive naturals, for example, 62464988 + ... + 62467569.

It is an arithmetic number, because the mean of its divisors is an integer number (40353216234).

Almost surely, 2^161287931087 is an apocalyptic number.

161287931087 is a deficient number, since it is larger than the sum of its proper divisors (124933849).

161287931087 is a wasteful number, since it uses less digits than its factorization.

161287931087 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124933848.

The product of its (nonzero) digits is 1016064, while the sum is 53.

The spelling of 161287931087 in words is "one hundred sixty-one billion, two hundred eighty-seven million, nine hundred thirty-one thousand, eighty-seven".