161245221 has 16 divisors (see below), whose sum is σ = 227976768. Its totient is φ = 101024000.

The previous prime is 161245211. The next prime is 161245283. The reversal of 161245221 is 122542161.

It is a cyclic number.

It is not a de Polignac number, because 161245221 - 2⁷ = 161245093 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 161245191 and 161245200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161245211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39946 + ... + 43796.

It is an arithmetic number, because the mean of its divisors is an integer number (14248548).

Almost surely, 2^161245221 is an apocalyptic number.

It is an amenable number.

161245221 is a deficient number, since it is larger than the sum of its proper divisors (66731547).

161245221 is a wasteful number, since it uses less digits than its factorization.

161245221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4692.

The product of its digits is 960, while the sum is 24.

The square root of 161245221 is about 12698.2369248648. The cubic root of 161245221 is about 544.2882395587.

Adding to 161245221 its reverse (122542161), we get a palindrome (283787382).

The spelling of 161245221 in words is "one hundred sixty-one million, two hundred forty-five thousand, two hundred twenty-one".