721566677855 has 4 divisors (see below), whose sum is σ = 865880013432. Its totient is φ = 577253342280.

The previous prime is 721566677827. The next prime is 721566677873. The reversal of 721566677855 is 558776665127.

721566677855 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 721566677855 - 2⁸ = 721566677599 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 721566677791 and 721566677800.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72156667781 + ... + 72156667790.

It is an arithmetic number, because the mean of its divisors is an integer number (216470003358).

Almost surely, 2^721566677855 is an apocalyptic number.

721566677855 is a deficient number, since it is larger than the sum of its proper divisors (144313335577).

721566677855 is a wasteful number, since it uses less digits than its factorization.

721566677855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144313335576.

The product of its digits is 148176000, while the sum is 65.

The spelling of 721566677855 in words is "seven hundred twenty-one billion, five hundred sixty-six million, six hundred seventy-seven thousand, eight hundred fifty-five".