723491891057 has 4 divisors (see below), whose sum is σ = 779145113460. Its totient is φ = 667838668656.

The previous prime is 723491891009. The next prime is 723491891119. The reversal of 723491891057 is 750198194327.

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 170251963456 + 553239927601 = 412616^2 + 743801^2 .

It is a cyclic number.

It is not a de Polignac number, because 723491891057 - 2²⁴ = 723475113841 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 723491890993 and 723491891011.

It is not an unprimeable number, because it can be changed into a prime (723491891557) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27826611182 + ... + 27826611207.

It is an arithmetic number, because the mean of its divisors is an integer number (194786278365).

Almost surely, 2^723491891057 is an apocalyptic number.

It is an amenable number.

723491891057 is a deficient number, since it is larger than the sum of its proper divisors (55653222403).

723491891057 is a wasteful number, since it uses less digits than its factorization.

723491891057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55653222402.

The product of its (nonzero) digits is 3810240, while the sum is 56.

The spelling of 723491891057 in words is "seven hundred twenty-three billion, four hundred ninety-one million, eight hundred ninety-one thousand, fifty-seven".