121755721215 has 16 divisors (see below), whose sum is σ = 194833395936. Its totient is φ = 64928304000.

The previous prime is 121755721211. The next prime is 121755721229. The reversal of 121755721215 is 512127557121.

It is not a de Polignac number, because 121755721215 - 2² = 121755721211 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121755721211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 379476 + ... + 622505.

It is an arithmetic number, because the mean of its divisors is an integer number (12177087246).

Almost surely, 2^121755721215 is an apocalyptic number.

121755721215 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

121755721215 is a deficient number, since it is larger than the sum of its proper divisors (73077674721).

121755721215 is a wasteful number, since it uses less digits than its factorization.

121755721215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1010090.

The product of its digits is 49000, while the sum is 39.

The spelling of 121755721215 in words is "one hundred twenty-one billion, seven hundred fifty-five million, seven hundred twenty-one thousand, two hundred fifteen".