1229199721 has 8 divisors (see below), whose sum is σ = 1260035784. Its totient is φ = 1198404480.

The previous prime is 1229199707. The next prime is 1229199731. The reversal of 1229199721 is 1279919221.

It can be written as a sum of positive squares in 4 ways, for example, as 127690000 + 1101509721 = 11300^2 + 33189^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1229199721 - 2⁵ = 1229199689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1229199731) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56091 + ... + 74863.

It is an arithmetic number, because the mean of its divisors is an integer number (157504473).

Almost surely, 2^1229199721 is an apocalyptic number.

It is an amenable number.

1229199721 is a deficient number, since it is larger than the sum of its proper divisors (30836063).

1229199721 is a wasteful number, since it uses less digits than its factorization.

1229199721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20411.

The product of its digits is 40824, while the sum is 43.

The square root of 1229199721 is about 35059.9446805040. The cubic root of 1229199721 is about 1071.2088474747.

The spelling of 1229199721 in words is "one billion, two hundred twenty-nine million, one hundred ninety-nine thousand, seven hundred twenty-one".