721720010106 has 24 divisors (see below), whose sum is σ = 1563743743380. Its totient is φ = 240570712896.

The previous prime is 721720010101. The next prime is 721720010111. The reversal of 721720010106 is 601010027127.

721720010106 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (721720010101) and next prime (721720010111).

It can be written as a sum of positive squares in 2 ways, for example, as 579296043225 + 142423966881 = 761115^2 + 377391^2 .

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 721720010106.

It is not an unprimeable number, because it can be changed into a prime (721720010101) 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, 2201686 + ... + 2508158.

Almost surely, 2^721720010106 is an apocalyptic number.

721720010106 is an abundant number, since it is smaller than the sum of its proper divisors (842023733274).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

721720010106 is a wasteful number, since it uses less digits than its factorization.

721720010106 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 437310 (or 437307 counting only the distinct ones).

The product of its (nonzero) digits is 1176, while the sum is 27.

The spelling of 721720010106 in words is "seven hundred twenty-one billion, seven hundred twenty million, ten thousand, one hundred six".