121971681 has 24 divisors (see below), whose sum is σ = 192419136. Its totient is φ = 73997280.

The previous prime is 121971649. The next prime is 121971683. The reversal of 121971681 is 186179121.

It is not a de Polignac number, because 121971681 - 2⁵ = 121971649 is a prime.

It is a super-2 number, since 2×121971681² = 29754181931931522, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (121971683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 966 + ... + 15648.

It is an arithmetic number, because the mean of its divisors is an integer number (8017464).

Almost surely, 2^121971681 is an apocalyptic number.

It is an amenable number.

121971681 is a deficient number, since it is larger than the sum of its proper divisors (70447455).

121971681 is a wasteful number, since it uses less digits than its factorization.

121971681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14773 (or 14770 counting only the distinct ones).

The product of its digits is 6048, while the sum is 36.

The square root of 121971681 is about 11044.0790018906. The cubic root of 121971681 is about 495.9291882629.

It can be divided in two parts, 1219 and 71681, that added together give a square (72900 = 270²).

The spelling of 121971681 in words is "one hundred twenty-one million, nine hundred seventy-one thousand, six hundred eighty-one".