161020331 has 2 divisors, whose sum is σ = 161020332. Its totient is φ = 161020330.

The previous prime is 161020283. The next prime is 161020333. The reversal of 161020331 is 133020161.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 161020331 - 2¹⁰ = 161019307 is a prime.

It is a super-2 number, since 2×161020331² = 51855093990699122, which contains 22 as substring.

Together with 161020333, 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 (161020333) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80510165 + 80510166.

It is an arithmetic number, because the mean of its divisors is an integer number (80510166).

Almost surely, 2^161020331 is an apocalyptic number.

161020331 is a deficient number, since it is larger than the sum of its proper divisors (1).

161020331 is an equidigital number, since it uses as much as digits as its factorization.

161020331 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 161020331 is about 12689.3786687923. The cubic root of 161020331 is about 544.0350807737.

Adding to 161020331 its reverse (133020161), we get a palindrome (294040492).

The spelling of 161020331 in words is "one hundred sixty-one million, twenty thousand, three hundred thirty-one".