800101721 has 4 divisors (see below), whose sum is σ = 800240292. Its totient is φ = 799963152.

The previous prime is 800101717. The next prime is 800101733. The reversal of 800101721 is 127101008.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 311028496 + 489073225 = 17636^2 + 22115^2 .

It is a cyclic number.

It is not a de Polignac number, because 800101721 - 2² = 800101717 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 800101693 and 800101702.

It is not an unprimeable number, because it can be changed into a prime (800101711) 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, 60230 + ... + 72303.

It is an arithmetic number, because the mean of its divisors is an integer number (200060073).

Almost surely, 2^800101721 is an apocalyptic number.

It is an amenable number.

800101721 is a deficient number, since it is larger than the sum of its proper divisors (138571).

800101721 is a wasteful number, since it uses less digits than its factorization.

800101721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138570.

The product of its (nonzero) digits is 112, while the sum is 20.

The square root of 800101721 is about 28286.0693805272. The cubic root of 800101721 is about 928.3571106432.

Adding to 800101721 its reverse (127101008), we get a palindrome (927202729).

The spelling of 800101721 in words is "eight hundred million, one hundred one thousand, seven hundred twenty-one".