121636551 has 16 divisors (see below), whose sum is σ = 166310144. Its totient is φ = 79035264.

The previous prime is 121636549. The next prime is 121636553. The reversal of 121636551 is 155636121.

It is an interprime number because it is at equal distance from previous prime (121636549) and next prime (121636553).

It is not a de Polignac number, because 121636551 - 2¹ = 121636549 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121636553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 93135 + ... + 94431.

It is an arithmetic number, because the mean of its divisors is an integer number (10394384).

Almost surely, 2^121636551 is an apocalyptic number.

121636551 is a deficient number, since it is larger than the sum of its proper divisors (44673593).

121636551 is a wasteful number, since it uses less digits than its factorization.

121636551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2070.

The product of its digits is 5400, while the sum is 30.

The square root of 121636551 is about 11028.8961823022. The cubic root of 121636551 is about 495.4745657957.

The spelling of 121636551 in words is "one hundred twenty-one million, six hundred thirty-six thousand, five hundred fifty-one".