20730757 has 2 divisors, whose sum is σ = 20730758. Its totient is φ = 20730756.

The previous prime is 20730739. The next prime is 20730781. The reversal of 20730757 is 75703702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16532356 + 4198401 = 4066^2 + 2049^2 .

It is a cyclic number.

It is not a de Polignac number, because 20730757 - 2²³ = 12342149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20731757) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10365378 + 10365379.

It is an arithmetic number, because the mean of its divisors is an integer number (10365379).

Almost surely, 2^20730757 is an apocalyptic number.

It is an amenable number.

20730757 is a deficient number, since it is larger than the sum of its proper divisors (1).

20730757 is an equidigital number, since it uses as much as digits as its factorization.

20730757 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10290, while the sum is 31.

The square root of 20730757 is about 4553.1041059919. The cubic root of 20730757 is about 274.7082614123.

The spelling of 20730757 in words is "twenty million, seven hundred thirty thousand, seven hundred fifty-seven".