705438721 has 4 divisors (see below), whose sum is σ = 759703252. Its totient is φ = 651174192.

The previous prime is 705438719. The next prime is 705438787. The reversal of 705438721 is 127834507.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 127834507 = 1097 ⋅116531.

It can be written as a sum of positive squares in 2 ways, for example, as 481188096 + 224250625 = 21936^2 + 14975^2 .

It is a cyclic number.

It is not a de Polignac number, because 705438721 - 2¹ = 705438719 is a prime.

It is a super-2 number, since 2×705438721² = 995287578172231682, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (705438421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27132246 + ... + 27132271.

It is an arithmetic number, because the mean of its divisors is an integer number (189925813).

Almost surely, 2^705438721 is an apocalyptic number.

It is an amenable number.

705438721 is a deficient number, since it is larger than the sum of its proper divisors (54264531).

705438721 is a wasteful number, since it uses less digits than its factorization.

705438721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54264530.

The product of its (nonzero) digits is 47040, while the sum is 37.

The square root of 705438721 is about 26560.0964041925. The cubic root of 705438721 is about 890.1976251793.

The spelling of 705438721 in words is "seven hundred five million, four hundred thirty-eight thousand, seven hundred twenty-one".