161687741 has 2 divisors, whose sum is σ = 161687742. Its totient is φ = 161687740.

The previous prime is 161687737. The next prime is 161687791. The reversal of 161687741 is 147786161.

161687741 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 161544100 + 143641 = 12710^2 + 379^2 .

It is a cyclic number.

It is not a de Polignac number, because 161687741 - 2² = 161687737 is a prime.

It is a super-2 number, since 2×161687741² = 52285851179366162, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161687791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80843870 + 80843871.

It is an arithmetic number, because the mean of its divisors is an integer number (80843871).

Almost surely, 2^161687741 is an apocalyptic number.

It is an amenable number.

161687741 is a deficient number, since it is larger than the sum of its proper divisors (1).

161687741 is an equidigital number, since it uses as much as digits as its factorization.

161687741 is an evil number, because the sum of its binary digits is even.

The product of its digits is 56448, while the sum is 41.

The square root of 161687741 is about 12715.6494525447. The cubic root of 161687741 is about 544.7856980860.

The spelling of 161687741 in words is "one hundred sixty-one million, six hundred eighty-seven thousand, seven hundred forty-one".