161261411566 has 8 divisors (see below), whose sum is σ = 254623281480. Its totient is φ = 76386984408.

The previous prime is 161261411557. The next prime is 161261411603. The reversal of 161261411566 is 665114162161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent 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, 2121860641 + ... + 2121860716.

It is an arithmetic number, because the mean of its divisors is an integer number (31827910185).

Almost surely, 2^161261411566 is an apocalyptic number.

161261411566 is a deficient number, since it is larger than the sum of its proper divisors (93361869914).

161261411566 is a wasteful number, since it uses less digits than its factorization.

161261411566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4243721378.

The product of its digits is 51840, while the sum is 40.

The spelling of 161261411566 in words is "one hundred sixty-one billion, two hundred sixty-one million, four hundred eleven thousand, five hundred sixty-six".