20724802849 has 2 divisors, whose sum is σ = 20724802850. Its totient is φ = 20724802848.

The previous prime is 20724802841. The next prime is 20724802873. The reversal of 20724802849 is 94820842702.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16394241600 + 4330561249 = 128040^2 + 65807^2 .

It is a cyclic number.

It is not a de Polignac number, because 20724802849 - 2³ = 20724802841 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20724802799 and 20724802808.

It is not a weakly prime, because it can be changed into another prime (20724802841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10362401424 + 10362401425.

It is an arithmetic number, because the mean of its divisors is an integer number (10362401425).

Almost surely, 2^20724802849 is an apocalyptic number.

It is an amenable number.

20724802849 is a deficient number, since it is larger than the sum of its proper divisors (1).

20724802849 is an equidigital number, since it uses as much as digits as its factorization.

20724802849 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 516096, while the sum is 46.

The spelling of 20724802849 in words is "twenty billion, seven hundred twenty-four million, eight hundred two thousand, eight hundred forty-nine".