161026221 has 16 divisors (see below), whose sum is σ = 217350144. Its totient is φ = 106034544.

The previous prime is 161026211. The next prime is 161026267. The reversal of 161026221 is 122620161.

It is not a de Polignac number, because 161026221 - 2⁵ = 161026189 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161026211) 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, 99400 + ... + 101006.

It is an arithmetic number, because the mean of its divisors is an integer number (13584384).

Almost surely, 2^161026221 is an apocalyptic number.

It is an amenable number.

161026221 is a deficient number, since it is larger than the sum of its proper divisors (56323923).

161026221 is a wasteful number, since it uses less digits than its factorization.

161026221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2000.

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 161026221 is about 12689.6107505313. The cubic root of 161026221 is about 544.0417141546.

Adding to 161026221 its reverse (122620161), we get a palindrome (283646382).

The spelling of 161026221 in words is "one hundred sixty-one million, twenty-six thousand, two hundred twenty-one".