668790072722 has 18 divisors (see below), whose sum is σ = 1010223381279. Its totient is φ = 332065190560.

The previous prime is 668790072553. The next prime is 668790072751. The reversal of 668790072722 is 227270097866.

It is a happy number.

It can be written as a sum of positive squares in 5 ways, for example, as 143210021761 + 525580050961 = 378431^2 + 724969^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=578269.

It is a super-2 number, since 2×668790072722² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 172322222 + ... + 172326102.

Almost surely, 2^668790072722 is an apocalyptic number.

668790072722 is a deficient number, since it is larger than the sum of its proper divisors (341433308557).

668790072722 is an frugal number, since it uses more digits than its factorization.

668790072722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8062 (or 4032 counting only the distinct ones).

The product of its (nonzero) digits is 7112448, while the sum is 56.

The spelling of 668790072722 in words is "six hundred sixty-eight billion, seven hundred ninety million, seventy-two thousand, seven hundred twenty-two".