161078779491 has 48 divisors (see below), whose sum is σ = 269152450560. Its totient is φ = 83835970560.

The previous prime is 161078779487. The next prime is 161078779493. The reversal of 161078779491 is 194977870161.

It is not a de Polignac number, because 161078779491 - 2² = 161078779487 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161078779493) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 239946 + ... + 616223.

It is an arithmetic number, because the mean of its divisors is an integer number (5607342720).

Almost surely, 2^161078779491 is an apocalyptic number.

161078779491 is a deficient number, since it is larger than the sum of its proper divisors (108073671069).

161078779491 is a wasteful number, since it uses less digits than its factorization.

161078779491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 856244 (or 856227 counting only the distinct ones).

The product of its (nonzero) digits is 5334336, while the sum is 60.

The spelling of 161078779491 in words is "one hundred sixty-one billion, seventy-eight million, seven hundred seventy-nine thousand, four hundred ninety-one".