161671752493 has 8 divisors (see below), whose sum is σ = 169537692600. Its totient is φ = 153958549248.

The previous prime is 161671752491. The next prime is 161671752497. The reversal of 161671752493 is 394257176161.

It can be written as a sum of positive squares in 4 ways, for example, as 631667689 + 161040084804 = 25133^2 + 401298^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 161671752493 - 2¹ = 161671752491 is a prime.

It is a super-2 number, since 2×161671752493² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 161671752493.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161671752491) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38182048 + ... + 38186281.

It is an arithmetic number, because the mean of its divisors is an integer number (21192211575).

Almost surely, 2^161671752493 is an apocalyptic number.

It is an amenable number.

161671752493 is a deficient number, since it is larger than the sum of its proper divisors (7865940107).

161671752493 is an equidigital number, since it uses as much as digits as its factorization.

161671752493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76368431.

The product of its digits is 1905120, while the sum is 52.

The spelling of 161671752493 in words is "one hundred sixty-one billion, six hundred seventy-one million, seven hundred fifty-two thousand, four hundred ninety-three".