721122444001345 has 4 divisors (see below), whose sum is σ = 865346932801620. Its totient is φ = 576897955201072.

The previous prime is 721122444001327. The next prime is 721122444001357. The reversal of 721122444001345 is 543100444221127.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 112850933489424 + 608271510511921 = 10623132^2 + 24663161^2 .

It is a cyclic number.

It is not a de Polignac number, because 721122444001345 - 2³¹ = 721120296517697 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 721122444001298 and 721122444001307.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72112244400130 + ... + 72112244400139.

It is an arithmetic number, because the mean of its divisors is an integer number (216336733200405).

Almost surely, 2^{721122444001345} is an apocalyptic number.

It is an amenable number.

721122444001345 is a deficient number, since it is larger than the sum of its proper divisors (144224488800275).

721122444001345 is a wasteful number, since it uses less digits than its factorization.

721122444001345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144224488800274.

The product of its (nonzero) digits is 215040, while the sum is 40.

The spelling of 721122444001345 in words is "seven hundred twenty-one trillion, one hundred twenty-two billion, four hundred forty-four million, one thousand, three hundred forty-five".