161257505471 has 4 divisors (see below), whose sum is σ = 161262776472. Its totient is φ = 161252234472.

The previous prime is 161257505429. The next prime is 161257505543. The reversal of 161257505471 is 174505752161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 174505752161 = 13 ⋅13423519397.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161257505471 is a prime.

It is a super-3 number, since 3×161257505471³ (a number of 35 digits) contains 333 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 (161257505771) 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, 2589341 + ... + 2650886.

It is an arithmetic number, because the mean of its divisors is an integer number (40315694118).

Almost surely, 2^161257505471 is an apocalyptic number.

161257505471 is a deficient number, since it is larger than the sum of its proper divisors (5271001).

161257505471 is an equidigital number, since it uses as much as digits as its factorization.

161257505471 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5271000.

The product of its (nonzero) digits is 294000, while the sum is 44.

The spelling of 161257505471 in words is "one hundred sixty-one billion, two hundred fifty-seven million, five hundred five thousand, four hundred seventy-one".