161405749 has 2 divisors, whose sum is σ = 161405750. Its totient is φ = 161405748.

The previous prime is 161405737. The next prime is 161405753. The reversal of 161405749 is 947504161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 84088900 + 77316849 = 9170^2 + 8793^2 .

It is a cyclic number.

It is not a de Polignac number, because 161405749 - 2¹⁷ = 161274677 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161405759) 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, 80702874 + 80702875.

It is an arithmetic number, because the mean of its divisors is an integer number (80702875).

Almost surely, 2^161405749 is an apocalyptic number.

It is an amenable number.

161405749 is a deficient number, since it is larger than the sum of its proper divisors (1).

161405749 is an equidigital number, since it uses as much as digits as its factorization.

161405749 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30240, while the sum is 37.

The square root of 161405749 is about 12704.5562299515. The cubic root of 161405749 is about 544.4688020648.

The spelling of 161405749 in words is "one hundred sixty-one million, four hundred five thousand, seven hundred forty-nine".