161221526241 has 16 divisors (see below), whose sum is σ = 217585944576. Its totient is φ = 106169467856.

The previous prime is 161221526231. The next prime is 161221526261. The reversal of 161221526241 is 142625122161.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 161221526241 - 2⁵ = 161221526209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161221526201) 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, 1661716 + ... + 1756058.

It is an arithmetic number, because the mean of its divisors is an integer number (13599121536).

Almost surely, 2^161221526241 is an apocalyptic number.

It is an amenable number.

161221526241 is a deficient number, since it is larger than the sum of its proper divisors (56364418335).

161221526241 is an equidigital number, since it uses as much as digits as its factorization.

161221526241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101292.

The product of its digits is 11520, while the sum is 33.

The spelling of 161221526241 in words is "one hundred sixty-one billion, two hundred twenty-one million, five hundred twenty-six thousand, two hundred forty-one".