705716721 has 6 divisors (see below), whose sum is σ = 1019368610. Its totient is φ = 470477808.

The previous prime is 705716701. The next prime is 705716741. The reversal of 705716721 is 127617507.

705716721 is a `hidden beast` number, since 7 + 0 + 571 + 67 + 21 = 666.

It is an interprime number because it is at equal distance from previous prime (705716701) and next prime (705716741).

It can be written as a sum of positive squares in only one way, i.e., 653313600 + 52403121 = 25560^2 + 7239^2 .

It is not a de Polignac number, because 705716721 - 2⁶ = 705716657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (705716701) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 39206476 + ... + 39206493.

Almost surely, 2^705716721 is an apocalyptic number.

It is an amenable number.

705716721 is a deficient number, since it is larger than the sum of its proper divisors (313651889).

705716721 is a wasteful number, since it uses less digits than its factorization.

705716721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78412975 (or 78412972 counting only the distinct ones).

The product of its (nonzero) digits is 20580, while the sum is 36.

The square root of 705716721 is about 26565.3293034361. The cubic root of 705716721 is about 890.3145464800.

The spelling of 705716721 in words is "seven hundred five million, seven hundred sixteen thousand, seven hundred twenty-one".