161131203515 has 4 divisors (see below), whose sum is σ = 193357444224. Its totient is φ = 128904962808.

The previous prime is 161131203487. The next prime is 161131203587. The reversal of 161131203515 is 515302131161.

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 161131203515 - 2³⁶ = 92411726779 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16113120347 + ... + 16113120356.

It is an arithmetic number, because the mean of its divisors is an integer number (48339361056).

Almost surely, 2^161131203515 is an apocalyptic number.

161131203515 is a deficient number, since it is larger than the sum of its proper divisors (32226240709).

161131203515 is an equidigital number, since it uses as much as digits as its factorization.

161131203515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32226240708.

The product of its (nonzero) digits is 2700, while the sum is 29.

Adding to 161131203515 its reverse (515302131161), we get a palindrome (676433334676).

The spelling of 161131203515 in words is "one hundred sixty-one billion, one hundred thirty-one million, two hundred three thousand, five hundred fifteen".