121620571755 has 8 divisors (see below), whose sum is σ = 194592914832. Its totient is φ = 64864304928.

The previous prime is 121620571753. The next prime is 121620571763. The reversal of 121620571755 is 557175026121.

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

It is not a de Polignac number, because 121620571755 - 2¹ = 121620571753 is a prime.

It is not an unprimeable number, because it can be changed into a prime (121620571753) 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, 4054019044 + ... + 4054019073.

It is an arithmetic number, because the mean of its divisors is an integer number (24324114354).

Almost surely, 2^121620571755 is an apocalyptic number.

121620571755 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

121620571755 is a deficient number, since it is larger than the sum of its proper divisors (72972343077).

121620571755 is an equidigital number, since it uses as much as digits as its factorization.

121620571755 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8108038125.

The product of its (nonzero) digits is 147000, while the sum is 42.

Adding to 121620571755 its reverse (557175026121), we get a palindrome (678795597876).

The spelling of 121620571755 in words is "one hundred twenty-one billion, six hundred twenty million, five hundred seventy-one thousand, seven hundred fifty-five".