161208849431 has 12 divisors (see below), whose sum is σ = 187735470408. Its totient is φ = 138026628432.

The previous prime is 161208849421. The next prime is 161208849493. The reversal of 161208849431 is 134948802161.

It is a happy number.

It is not a de Polignac number, because 161208849431 - 2¹⁰ = 161208848407 is a prime.

It is a super-2 number, since 2×161208849431² (a number of 23 digits) contains 22 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 (161208849421) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1769216 + ... + 1858101.

It is an arithmetic number, because the mean of its divisors is an integer number (15644622534).

Almost surely, 2^161208849431 is an apocalyptic number.

161208849431 is a deficient number, since it is larger than the sum of its proper divisors (26526620977).

161208849431 is an equidigital number, since it uses as much as digits as its factorization.

161208849431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3628238 (or 3628231 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 47.

The spelling of 161208849431 in words is "one hundred sixty-one billion, two hundred eight million, eight hundred forty-nine thousand, four hundred thirty-one".