20723513 has 2 divisors, whose sum is σ = 20723514. Its totient is φ = 20723512.

The previous prime is 20723503. The next prime is 20723519. The reversal of 20723513 is 31532702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20720704 + 2809 = 4552^2 + 53^2 .

It is a cyclic number.

It is not a de Polignac number, because 20723513 - 2⁶ = 20723449 is a prime.

It is a super-2 number, since 2×20723513² = 858927982122338, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20723519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10361756 + 10361757.

It is an arithmetic number, because the mean of its divisors is an integer number (10361757).

Almost surely, 2^20723513 is an apocalyptic number.

It is an amenable number.

20723513 is a deficient number, since it is larger than the sum of its proper divisors (1).

20723513 is an equidigital number, since it uses as much as digits as its factorization.

20723513 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1260, while the sum is 23.

The square root of 20723513 is about 4552.3085352379. The cubic root of 20723513 is about 274.6762603542.

The spelling of 20723513 in words is "twenty million, seven hundred twenty-three thousand, five hundred thirteen".