121437681 has 16 divisors (see below), whose sum is σ = 174680064. Its totient is φ = 74756864.

The previous prime is 121437671. The next prime is 121437713. The reversal of 121437681 is 186734121.

It is a cyclic number.

It is not a de Polignac number, because 121437681 - 2⁷ = 121437553 is a prime.

It is a super-2 number, since 2×121437681² = 29494220733315522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (121437601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19761 + ... + 25166.

It is an arithmetic number, because the mean of its divisors is an integer number (10917504).

Almost surely, 2^121437681 is an apocalyptic number.

It is an amenable number.

121437681 is a deficient number, since it is larger than the sum of its proper divisors (53242383).

121437681 is a wasteful number, since it uses less digits than its factorization.

121437681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45000.

The product of its digits is 8064, while the sum is 33.

The square root of 121437681 is about 11019.8766327033. The cubic root of 121437681 is about 495.2043926859.

The spelling of 121437681 in words is "one hundred twenty-one million, four hundred thirty-seven thousand, six hundred eighty-one".