165961471031 has 4 divisors (see below), whose sum is σ = 170446916232. Its totient is φ = 161476025832.

The previous prime is 165961471021. The next prime is 165961471043. The reversal of 165961471031 is 130174169561.

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 165961471031 - 2¹⁰ = 165961470007 is a prime.

It is a super-3 number, since 3×165961471031³ (a number of 35 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165961471021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2242722545 + ... + 2242722618.

It is an arithmetic number, because the mean of its divisors is an integer number (42611729058).

Almost surely, 2^165961471031 is an apocalyptic number.

165961471031 is a deficient number, since it is larger than the sum of its proper divisors (4485445201).

165961471031 is an equidigital number, since it uses as much as digits as its factorization.

165961471031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4485445200.

The product of its (nonzero) digits is 136080, while the sum is 44.

The spelling of 165961471031 in words is "one hundred sixty-five billion, nine hundred sixty-one million, four hundred seventy-one thousand, thirty-one".