706221661 has 4 divisors (see below), whose sum is σ = 719546652. Its totient is φ = 692896672.

The previous prime is 706221653. The next prime is 706221673. The reversal of 706221661 is 166122607.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 166122607 = 7 ⋅23731801.

It can be written as a sum of positive squares in 2 ways, for example, as 194602500 + 511619161 = 13950^2 + 22619^2 .

It is a cyclic number.

It is not a de Polignac number, because 706221661 - 2³ = 706221653 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 (706221611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6662416 + ... + 6662521.

It is an arithmetic number, because the mean of its divisors is an integer number (179886663).

Almost surely, 2^706221661 is an apocalyptic number.

It is an amenable number.

706221661 is a deficient number, since it is larger than the sum of its proper divisors (13324991).

706221661 is a wasteful number, since it uses less digits than its factorization.

706221661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13324990.

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 706221661 is about 26574.8313447141. The cubic root of 706221661 is about 890.5268357444.

The spelling of 706221661 in words is "seven hundred six million, two hundred twenty-one thousand, six hundred sixty-one".