121565721063 has 16 divisors (see below), whose sum is σ = 167920326656. Its totient is φ = 78146341920.

The previous prime is 121565721061. The next prime is 121565721083. The reversal of 121565721063 is 360127565121.

It is not a de Polignac number, because 121565721063 - 2¹ = 121565721061 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121565721061) 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, 2333731 + ... + 2385252.

It is an arithmetic number, because the mean of its divisors is an integer number (10495020416).

Almost surely, 2^121565721063 is an apocalyptic number.

121565721063 is a deficient number, since it is larger than the sum of its proper divisors (46354605593).

121565721063 is a wasteful number, since it uses less digits than its factorization.

121565721063 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4719294.

The product of its (nonzero) digits is 75600, while the sum is 39.

The spelling of 121565721063 in words is "one hundred twenty-one billion, five hundred sixty-five million, seven hundred twenty-one thousand, sixty-three".