121751532721 has 32 divisors (see below), whose sum is σ = 153677905920. Its totient is φ = 93886019136.

The previous prime is 121751532713. The next prime is 121751532731. The reversal of 121751532721 is 127235157121.

It is not a de Polignac number, because 121751532721 - 2³ = 121751532713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (121751532731) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 962650 + ... + 1081756.

It is an arithmetic number, because the mean of its divisors is an integer number (4802434560).

Almost surely, 2^121751532721 is an apocalyptic number.

It is an amenable number.

121751532721 is a deficient number, since it is larger than the sum of its proper divisors (31926373199).

121751532721 is a wasteful number, since it uses less digits than its factorization.

121751532721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119413.

The product of its digits is 29400, while the sum is 37.

Adding to 121751532721 its reverse (127235157121), we get a palindrome (248986689842).

The spelling of 121751532721 in words is "one hundred twenty-one billion, seven hundred fifty-one million, five hundred thirty-two thousand, seven hundred twenty-one".