161451761 has 2 divisors, whose sum is σ = 161451762. Its totient is φ = 161451760.

The previous prime is 161451739. The next prime is 161451791. The reversal of 161451761 is 167154161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 93702400 + 67749361 = 9680^2 + 8231^2 .

It is an emirp because it is prime and its reverse (167154161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 161451761 - 2¹⁴ = 161435377 is a prime.

It is a super-2 number, since 2×161451761² = 52133342260002242, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (161451791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80725880 + 80725881.

It is an arithmetic number, because the mean of its divisors is an integer number (80725881).

Almost surely, 2^161451761 is an apocalyptic number.

It is an amenable number.

161451761 is a deficient number, since it is larger than the sum of its proper divisors (1).

161451761 is an equidigital number, since it uses as much as digits as its factorization.

161451761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5040, while the sum is 32.

The square root of 161451761 is about 12706.3669473221. The cubic root of 161451761 is about 544.5205344608.

The spelling of 161451761 in words is "one hundred sixty-one million, four hundred fifty-one thousand, seven hundred sixty-one".