721522660105 has 16 divisors (see below), whose sum is σ = 934001727120. Its totient is φ = 531918194688.

The previous prime is 721522660087. The next prime is 721522660139. The reversal of 721522660105 is 501066225127.

721522660105 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 202281359049 + 519241301056 = 449757^2 + 720584^2 .

It is a cyclic number.

It is not a de Polignac number, because 721522660105 - 2¹⁷ = 721522529033 is a prime.

It is a super-2 number, since 2×721522660105² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9320940 + ... + 9398029.

It is an arithmetic number, because the mean of its divisors is an integer number (58375107945).

Almost surely, 2^721522660105 is an apocalyptic number.

It is an amenable number.

721522660105 is a deficient number, since it is larger than the sum of its proper divisors (212479067015).

721522660105 is a wasteful number, since it uses less digits than its factorization.

721522660105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18719580.

The product of its (nonzero) digits is 50400, while the sum is 37.

The spelling of 721522660105 in words is "seven hundred twenty-one billion, five hundred twenty-two million, six hundred sixty thousand, one hundred five".