20315255549 has 2 divisors, whose sum is σ = 20315255550. Its totient is φ = 20315255548.

The previous prime is 20315255539. The next prime is 20315255567. The reversal of 20315255549 is 94555251302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18092133049 + 2223122500 = 134507^2 + 47150^2 .

It is a cyclic number.

It is not a de Polignac number, because 20315255549 - 2⁴ = 20315255533 is a prime.

It is a super-3 number, since 3×20315255549³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20315255509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10157627774 + 10157627775.

It is an arithmetic number, because the mean of its divisors is an integer number (10157627775).

Almost surely, 2^20315255549 is an apocalyptic number.

It is an amenable number.

20315255549 is a deficient number, since it is larger than the sum of its proper divisors (1).

20315255549 is an equidigital number, since it uses as much as digits as its factorization.

20315255549 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 270000, while the sum is 41.

The spelling of 20315255549 in words is "twenty billion, three hundred fifteen million, two hundred fifty-five thousand, five hundred forty-nine".