161869481 has 2 divisors, whose sum is σ = 161869482. Its totient is φ = 161869480.

The previous prime is 161869471. The next prime is 161869483. The reversal of 161869481 is 184968161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 159163456 + 2706025 = 12616^2 + 1645^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161869481 is a prime.

It is a super-2 number, since 2×161869481² = 52403457758418722, which contains 22 as substring.

Together with 161869483, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (161869483) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80934740 + 80934741.

It is an arithmetic number, because the mean of its divisors is an integer number (80934741).

Almost surely, 2^161869481 is an apocalyptic number.

It is an amenable number.

161869481 is a deficient number, since it is larger than the sum of its proper divisors (1).

161869481 is an equidigital number, since it uses as much as digits as its factorization.

161869481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 82944, while the sum is 44.

The square root of 161869481 is about 12722.7937576619. The cubic root of 161869481 is about 544.9897380443.

The spelling of 161869481 in words is "one hundred sixty-one million, eight hundred sixty-nine thousand, four hundred eighty-one".