121756636 has 18 divisors (see below), whose sum is σ = 224881440. Its totient is φ = 57673512.

The previous prime is 121756619. The next prime is 121756643. The reversal of 121756636 is 636657121.

121756636 = T₉₀₀₈ + T₉₀₀₉ + T₉₀₁₀.

121756636 is digitally balanced in base 9, because in such base it contains all the possibile digits an equal number of times.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

121756636 is strictly pandigital in base 9.

It is a junction number, because it is equal to n+sod(n) for n = 121756595 and 121756604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 40716 + ... + 43603.

Almost surely, 2^121756636 is an apocalyptic number.

121756636 is the 9010-th centered triangular number.

It is an amenable number.

121756636 is a deficient number, since it is larger than the sum of its proper divisors (103124804).

121756636 is a wasteful number, since it uses less digits than its factorization.

121756636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84361 (or 84340 counting only the distinct ones).

The product of its digits is 45360, while the sum is 37.

The square root of 121756636 is about 11034.3389471232. The cubic root of 121756636 is about 495.6375636595.

The spelling of 121756636 in words is "one hundred twenty-one million, seven hundred fifty-six thousand, six hundred thirty-six".