121807961 has 4 divisors (see below), whose sum is σ = 132881424. Its totient is φ = 110734500.

The previous prime is 121807957. The next prime is 121807969. The reversal of 121807961 is 169708121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 169708121 = 11 ⋅15428011.

It is a cyclic number.

It is not a de Polignac number, because 121807961 - 2² = 121807957 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (121807969) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5536715 + ... + 5536736.

It is an arithmetic number, because the mean of its divisors is an integer number (33220356).

Almost surely, 2^121807961 is an apocalyptic number.

121807961 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121807961 is a deficient number, since it is larger than the sum of its proper divisors (11073463).

121807961 is a wasteful number, since it uses less digits than its factorization.

121807961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11073462.

The product of its (nonzero) digits is 6048, while the sum is 35.

The square root of 121807961 is about 11036.6643964560. The cubic root of 121807961 is about 495.7071971656.

The spelling of 121807961 in words is "one hundred twenty-one million, eight hundred seven thousand, nine hundred sixty-one".