721453194397 has 6 divisors (see below), whose sum is σ = 781218547962. Its totient is φ = 665956794672.

The previous prime is 721453194379. The next prime is 721453194403. The reversal of 721453194397 is 793491354127.

It can be written as a sum of positive squares in 3 ways, for example, as 4474405881 + 716978788516 = 66891^2 + 846746^2 .

It is not a de Polignac number, because 721453194397 - 2²³ = 721444805789 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 (721453194797) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2134476738 + ... + 2134477075.

It is an arithmetic number, because the mean of its divisors is an integer number (130203091327).

Almost surely, 2^721453194397 is an apocalyptic number.

It is an amenable number.

721453194397 is a deficient number, since it is larger than the sum of its proper divisors (59765353565).

721453194397 is a wasteful number, since it uses less digits than its factorization.

721453194397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4268953839 (or 4268953826 counting only the distinct ones).

The product of its digits is 5715360, while the sum is 55.

The spelling of 721453194397 in words is "seven hundred twenty-one billion, four hundred fifty-three million, one hundred ninety-four thousand, three hundred ninety-seven".