730565921 has 4 divisors (see below), whose sum is σ = 748384644. Its totient is φ = 712747200.

The previous prime is 730565911. The next prime is 730565971. The reversal of 730565921 is 129565037.

It is a happy number.

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 40768225 + 689797696 = 6385^2 + 26264^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-730565921 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (730565911) 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, 8909300 + ... + 8909381.

It is an arithmetic number, because the mean of its divisors is an integer number (187096161).

Almost surely, 2^730565921 is an apocalyptic number.

It is an amenable number.

730565921 is a deficient number, since it is larger than the sum of its proper divisors (17818723).

730565921 is a wasteful number, since it uses less digits than its factorization.

730565921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17818722.

The product of its (nonzero) digits is 56700, while the sum is 38.

The square root of 730565921 is about 27028.9829812370. The cubic root of 730565921 is about 900.6439510765.

The spelling of 730565921 in words is "seven hundred thirty million, five hundred sixty-five thousand, nine hundred twenty-one".