Search a number
1630729 = 12772

1630729 has 3 divisors (see below), whose sum is σ = 1632007. Its totient is φ = 1629452.

The previous prime is 1630721. The next prime is 1630763. The reversal of 1630729 is 9270361.

The square root of 1630729 is 1277.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 1071225 + 559504 = 1035^2 + 748^2 .

It is not a de Polignac number, because 1630729 - 23 = 1630721 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1630697 and 1630706.

It is not an unprimeable number, because it can be changed into a prime (1630721) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 639 + ... + 1915.

21630729 is an apocalyptic number.

1630729 is the 1277-th square number.

1630729 is the 639-th centered octagonal number.

It is an amenable number.

1630729 is a deficient number, since it is larger than the sum of its proper divisors (1278).

1630729 is an frugal number, since it uses more digits than its factorization.

1630729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2554 (or 1277 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 28.

The cubic root of 1630729 is about 117.7047343528.

The spelling of 1630729 in words is "one million, six hundred thirty thousand, seven hundred twenty-nine".

Divisors: 1 1277 1630729