121755724649 has 8 divisors (see below), whose sum is σ = 131196372552. Its totient is φ = 112325765760.

The previous prime is 121755724621. The next prime is 121755724663. The reversal of 121755724649 is 946427557121.

It can be written as a sum of positive squares in 4 ways, for example, as 308353600 + 121447371049 = 17560^2 + 348493^2 .

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

It is a de Polignac number, because none of the positive numbers 2^k-121755724649 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 121755724649.

It is not an unprimeable number, because it can be changed into a prime (121755724669) 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, 2648582 + ... + 2694159.

It is an arithmetic number, because the mean of its divisors is an integer number (16399546569).

Almost surely, 2^121755724649 is an apocalyptic number.

It is an amenable number.

121755724649 is a deficient number, since it is larger than the sum of its proper divisors (9440647903).

121755724649 is a wasteful number, since it uses less digits than its factorization.

121755724649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5344507.

The product of its digits is 4233600, while the sum is 53.

The spelling of 121755724649 in words is "one hundred twenty-one billion, seven hundred fifty-five million, seven hundred twenty-four thousand, six hundred forty-nine".