721766538401351 has 16 divisors (see below), whose sum is σ = 759825608066496. Its totient is φ = 684264169053696.

The previous prime is 721766538401317. The next prime is 721766538401357. The reversal of 721766538401351 is 153104835667127.

It is a cyclic number.

It is not a de Polignac number, because 721766538401351 - 2¹⁴ = 721766538384967 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 (721766538401357) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 152815961 + ... + 157468253.

It is an arithmetic number, because the mean of its divisors is an integer number (47489100504156).

Almost surely, 2^{721766538401351} is an apocalyptic number.

721766538401351 is a deficient number, since it is larger than the sum of its proper divisors (38059069665145).

721766538401351 is a wasteful number, since it uses less digits than its factorization.

721766538401351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4712122.

The product of its (nonzero) digits is 25401600, while the sum is 59.

The spelling of 721766538401351 in words is "seven hundred twenty-one trillion, seven hundred sixty-six billion, five hundred thirty-eight million, four hundred one thousand, three hundred fifty-one".