121681681 has 8 divisors (see below), whose sum is σ = 139730400. Its totient is φ = 104797440.

The previous prime is 121681667. The next prime is 121681697. The reversal of 121681681 is 186186121.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 121681681 - 2¹⁵ = 121648913 is a prime.

It is a super-2 number, since 2×121681681² = 29612862981971522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121681081) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 290896 + ... + 291313.

It is an arithmetic number, because the mean of its divisors is an integer number (17466300).

Almost surely, 2^121681681 is an apocalyptic number.

121681681 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121681681 is a deficient number, since it is larger than the sum of its proper divisors (18048719).

121681681 is a wasteful number, since it uses less digits than its factorization.

121681681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 582239.

The product of its digits is 4608, while the sum is 34.

The square root of 121681681 is about 11030.9419815354. The cubic root of 121681681 is about 495.5358357623.

The spelling of 121681681 in words is "one hundred twenty-one million, six hundred eighty-one thousand, six hundred eighty-one".