1630121729 has 4 divisors (see below), whose sum is σ = 1630267140. Its totient is φ = 1629976320.

The previous prime is 1630121707. The next prime is 1630121741. The reversal of 1630121729 is 9271210361.

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 607721104 + 1022400625 = 24652^2 + 31975^2 .

It is a cyclic number.

It is not a de Polignac number, because 1630121729 - 2¹² = 1630117633 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1630121695 and 1630121704.

It is not an unprimeable number, because it can be changed into a prime (1630421729) 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, 54344 + ... + 78825.

It is an arithmetic number, because the mean of its divisors is an integer number (407566785).

Almost surely, 2^1630121729 is an apocalyptic number.

It is an amenable number.

1630121729 is a deficient number, since it is larger than the sum of its proper divisors (145411).

1630121729 is a wasteful number, since it uses less digits than its factorization.

1630121729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145410.

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 1630121729 is about 40374.7659931299. The cubic root of 1630121729 is about 1176.9012175797.

The spelling of 1630121729 in words is "one billion, six hundred thirty million, one hundred twenty-one thousand, seven hundred twenty-nine".