121636910691 has 24 divisors (see below), whose sum is σ = 176505966000. Its totient is φ = 80718471936.

The previous prime is 121636910683. The next prime is 121636910713. The reversal of 121636910691 is 196019636121.

121636910691 is a `hidden beast` number, since 1 + 2 + 1 + 636 + 9 + 1 + 0 + 6 + 9 + 1 = 666.

It is not a de Polignac number, because 121636910691 - 2³ = 121636910683 is a prime.

It is not an unprimeable number, because it can be changed into a prime (121636910621) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9004060 + ... + 9017558.

It is an arithmetic number, because the mean of its divisors is an integer number (7354415250).

Almost surely, 2^121636910691 is an apocalyptic number.

121636910691 is a deficient number, since it is larger than the sum of its proper divisors (54869055309).

121636910691 is a wasteful number, since it uses less digits than its factorization.

121636910691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18035 (or 18032 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 45.

The spelling of 121636910691 in words is "one hundred twenty-one billion, six hundred thirty-six million, nine hundred ten thousand, six hundred ninety-one".