705287431621 has 4 divisors (see below), whose sum is σ = 705805645644. Its totient is φ = 704769217600.

The previous prime is 705287431573. The next prime is 705287431631. The reversal of 705287431621 is 126134782507.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 126134782507 = 4877 ⋅25863191.

It can be written as a sum of positive squares in 2 ways, for example, as 343712512900 + 361574918721 = 586270^2 + 601311^2 .

It is a cyclic number.

It is not a de Polignac number, because 705287431621 - 2⁷ = 705287431493 is a prime.

It is a super-2 number, since 2×705287431621² (a number of 24 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 (705287431631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 259104970 + ... + 259107691.

It is an arithmetic number, because the mean of its divisors is an integer number (176451411411).

Almost surely, 2^705287431621 is an apocalyptic number.

It is an amenable number.

705287431621 is a deficient number, since it is larger than the sum of its proper divisors (518214023).

705287431621 is a wasteful number, since it uses less digits than its factorization.

705287431621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 518214022.

The product of its (nonzero) digits is 564480, while the sum is 46.

The spelling of 705287431621 in words is "seven hundred five billion, two hundred eighty-seven million, four hundred thirty-one thousand, six hundred twenty-one".