121571561 has 2 divisors, whose sum is σ = 121571562. Its totient is φ = 121571560.

The previous prime is 121571551. The next prime is 121571617. The reversal of 121571561 is 165175121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 109599961 + 11971600 = 10469^2 + 3460^2 .

It is a cyclic number.

It is not a de Polignac number, because 121571561 - 2⁶ = 121571497 is a prime.

It is a super-3 number, since 3×121571561³ (a number of 25 digits) contains 333 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (121571501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60785780 + 60785781.

It is an arithmetic number, because the mean of its divisors is an integer number (60785781).

Almost surely, 2^121571561 is an apocalyptic number.

It is an amenable number.

121571561 is a deficient number, since it is larger than the sum of its proper divisors (1).

121571561 is an equidigital number, since it uses as much as digits as its factorization.

121571561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2100, while the sum is 29.

The square root of 121571561 is about 11025.9494375768. The cubic root of 121571561 is about 495.3863066104.

The spelling of 121571561 in words is "one hundred twenty-one million, five hundred seventy-one thousand, five hundred sixty-one".