721122705 has 12 divisors (see below), whose sum is σ = 1249946100. Its totient is φ = 384598752.

The previous prime is 721122683. The next prime is 721122707. The reversal of 721122705 is 507221127.

It can be written as a sum of positive squares in 2 ways, for example, as 224011089 + 497111616 = 14967^2 + 22296^2 .

It is not a de Polignac number, because 721122705 - 2⁶ = 721122641 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (721122707) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8012430 + ... + 8012519.

It is an arithmetic number, because the mean of its divisors is an integer number (104162175).

Almost surely, 2^721122705 is an apocalyptic number.

It is an amenable number.

721122705 is a deficient number, since it is larger than the sum of its proper divisors (528823395).

721122705 is a wasteful number, since it uses less digits than its factorization.

721122705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16024960 (or 16024957 counting only the distinct ones).

The product of its (nonzero) digits is 1960, while the sum is 27.

The square root of 721122705 is about 26853.7279534891. The cubic root of 721122705 is about 896.7465680761.

The spelling of 721122705 in words is "seven hundred twenty-one million, one hundred twenty-two thousand, seven hundred five".