121681951 has 2 divisors, whose sum is σ = 121681952. Its totient is φ = 121681950.

The previous prime is 121681943. The next prime is 121681993. The reversal of 121681951 is 159186121.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 121681951 - 2³ = 121681943 is a prime.

It is equal to p_6931915 and since 121681951 and 6931915 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121681921) 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 as a sum of consecutive naturals, namely, 60840975 + 60840976.

It is an arithmetic number, because the mean of its divisors is an integer number (60840976).

Almost surely, 2^121681951 is an apocalyptic number.

121681951 is a deficient number, since it is larger than the sum of its proper divisors (1).

121681951 is an equidigital number, since it uses as much as digits as its factorization.

121681951 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4320, while the sum is 34.

The square root of 121681951 is about 11030.9542198307. The cubic root of 121681951 is about 495.5362022776.

The spelling of 121681951 in words is "one hundred twenty-one million, six hundred eighty-one thousand, nine hundred fifty-one".