721617347447 has 8 divisors (see below), whose sum is σ = 730330599936. Its totient is φ = 712904549112.

The previous prime is 721617347443. The next prime is 721617347453. The reversal of 721617347447 is 744743716127.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 721617347447 - 2² = 721617347443 is a prime.

It is a super-2 number, since 2×721617347447² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721617347443) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3960218 + ... + 4138424.

It is an arithmetic number, because the mean of its divisors is an integer number (91291324992).

Almost surely, 2^721617347447 is an apocalyptic number.

721617347447 is a deficient number, since it is larger than the sum of its proper divisors (8713252489).

721617347447 is a wasteful number, since it uses less digits than its factorization.

721617347447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 227077.

The product of its digits is 5531904, while the sum is 53.

The spelling of 721617347447 in words is "seven hundred twenty-one billion, six hundred seventeen million, three hundred forty-seven thousand, four hundred forty-seven".