20356721053 has 2 divisors, whose sum is σ = 20356721054. Its totient is φ = 20356721052.

The previous prime is 20356721041. The next prime is 20356721059. The reversal of 20356721053 is 35012765302.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15395350084 + 4961370969 = 124078^2 + 70437^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20356721053 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20356721059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10178360526 + 10178360527.

It is an arithmetic number, because the mean of its divisors is an integer number (10178360527).

Almost surely, 2^20356721053 is an apocalyptic number.

It is an amenable number.

20356721053 is a deficient number, since it is larger than the sum of its proper divisors (1).

20356721053 is an equidigital number, since it uses as much as digits as its factorization.

20356721053 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 37800, while the sum is 34.

The spelling of 20356721053 in words is "twenty billion, three hundred fifty-six million, seven hundred twenty-one thousand, fifty-three".