121881581 has 2 divisors, whose sum is σ = 121881582. Its totient is φ = 121881580.

The previous prime is 121881569. The next prime is 121881629. The reversal of 121881581 is 185188121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 82065481 + 39816100 = 9059^2 + 6310^2 .

It is a cyclic number.

It is not a de Polignac number, because 121881581 - 2²⁶ = 54772717 is a prime.

It is a super-2 number, since 2×121881581² = 29710239574119122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121886581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60940790 + 60940791.

It is an arithmetic number, because the mean of its divisors is an integer number (60940791).

Almost surely, 2^121881581 is an apocalyptic number.

It is an amenable number.

121881581 is a deficient number, since it is larger than the sum of its proper divisors (1).

121881581 is an equidigital number, since it uses as much as digits as its factorization.

121881581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5120, while the sum is 35.

The square root of 121881581 is about 11039.9991394927. Note that the first 3 decimals coincide. The cubic root of 121881581 is about 495.8070445367.

The spelling of 121881581 in words is "one hundred twenty-one million, eight hundred eighty-one thousand, five hundred eighty-one".