161522551 has 2 divisors, whose sum is σ = 161522552. Its totient is φ = 161522550.

The previous prime is 161522549. The next prime is 161522561. The reversal of 161522551 is 155225161.

161522551 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 is a cyclic number.

It is not a de Polignac number, because 161522551 - 2¹ = 161522549 is a prime.

Together with 161522549, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161522561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80761275 + 80761276.

It is an arithmetic number, because the mean of its divisors is an integer number (80761276).

Almost surely, 2^161522551 is an apocalyptic number.

161522551 is a deficient number, since it is larger than the sum of its proper divisors (1).

161522551 is an equidigital number, since it uses as much as digits as its factorization.

161522551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3000, while the sum is 28.

The square root of 161522551 is about 12709.1522533960. The cubic root of 161522551 is about 544.6001061670.

The spelling of 161522551 in words is "one hundred sixty-one million, five hundred twenty-two thousand, five hundred fifty-one".