721166661127 has 8 divisors (see below), whose sum is σ = 796685840640. Its totient is φ = 647307243960.

The previous prime is 721166661113. The next prime is 721166661133.

721166661127 is nontrivially palindromic in base 10.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-721166661127 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 (721166661167) 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, 414939673 + ... + 414941410.

It is an arithmetic number, because the mean of its divisors is an integer number (99585730080).

Almost surely, 2^721166661127 is an apocalyptic number.

721166661127 is a deficient number, since it is larger than the sum of its proper divisors (75519179513).

721166661127 is a wasteful number, since it uses less digits than its factorization.

721166661127 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 829881173.

The product of its digits is 254016, while the sum is 46.

The spelling of 721166661127 in words is "seven hundred twenty-one billion, one hundred sixty-six million, six hundred sixty-one thousand, one hundred twenty-seven".