121973581 has 2 divisors, whose sum is σ = 121973582. Its totient is φ = 121973580.

The previous prime is 121973573. The next prime is 121973609. The reversal of 121973581 is 185379121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 102313225 + 19660356 = 10115^2 + 4434^2 .

It is a cyclic number.

It is not a de Polignac number, because 121973581 - 2³ = 121973573 is a prime.

It is a super-2 number, since 2×121973581² = 29755108923927122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 121973581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121973081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60986790 + 60986791.

It is an arithmetic number, because the mean of its divisors is an integer number (60986791).

Almost surely, 2^121973581 is an apocalyptic number.

It is an amenable number.

121973581 is a deficient number, since it is larger than the sum of its proper divisors (1).

121973581 is an equidigital number, since it uses as much as digits as its factorization.

121973581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15120, while the sum is 37.

The square root of 121973581 is about 11044.1650204984. The cubic root of 121973581 is about 495.9317633431.

The spelling of 121973581 in words is "one hundred twenty-one million, nine hundred seventy-three thousand, five hundred eighty-one".