20555513239 has 2 divisors, whose sum is σ = 20555513240. Its totient is φ = 20555513238.

The previous prime is 20555513227. The next prime is 20555513243. The reversal of 20555513239 is 93231555502.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20555513239 is a prime.

It is a super-2 number, since 2×20555513239² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20555513219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10277756619 + 10277756620.

It is an arithmetic number, because the mean of its divisors is an integer number (10277756620).

Almost surely, 2^20555513239 is an apocalyptic number.

20555513239 is a deficient number, since it is larger than the sum of its proper divisors (1).

20555513239 is an equidigital number, since it uses as much as digits as its factorization.

20555513239 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 202500, while the sum is 40.

The spelling of 20555513239 in words is "twenty billion, five hundred fifty-five million, five hundred thirteen thousand, two hundred thirty-nine".