161420551 has 2 divisors, whose sum is σ = 161420552. Its totient is φ = 161420550.

The previous prime is 161420543. The next prime is 161420569. The reversal of 161420551 is 155024161.

It is a happy number.

161420551 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 an emirp because it is prime and its reverse (155024161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 161420551 - 2³ = 161420543 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161420531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80710275 + 80710276.

It is an arithmetic number, because the mean of its divisors is an integer number (80710276).

Almost surely, 2^161420551 is an apocalyptic number.

161420551 is a deficient number, since it is larger than the sum of its proper divisors (1).

161420551 is an equidigital number, since it uses as much as digits as its factorization.

161420551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1200, while the sum is 25.

The square root of 161420551 is about 12705.1387635083. The cubic root of 161420551 is about 544.4854453812.

The spelling of 161420551 in words is "one hundred sixty-one million, four hundred twenty thousand, five hundred fifty-one".