20730961 has 4 divisors (see below), whose sum is σ = 20829424. Its totient is φ = 20632500.

The previous prime is 20730947. The next prime is 20730979. The reversal of 20730961 is 16903702.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16903702 = 2 ⋅8451851.

It is a cyclic number.

It is not a de Polignac number, because 20730961 - 2¹¹ = 20728913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20730991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48915 + ... + 49336.

It is an arithmetic number, because the mean of its divisors is an integer number (5207356).

Almost surely, 2^20730961 is an apocalyptic number.

It is an amenable number.

20730961 is a deficient number, since it is larger than the sum of its proper divisors (98463).

20730961 is an equidigital number, since it uses as much as digits as its factorization.

20730961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98462.

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

The square root of 20730961 is about 4553.1265082359. The cubic root of 20730961 is about 274.7091624938.

The spelling of 20730961 in words is "twenty million, seven hundred thirty thousand, nine hundred sixty-one".