20045542421 has 2 divisors, whose sum is σ = 20045542422. Its totient is φ = 20045542420.

The previous prime is 20045542379. The next prime is 20045542427. The reversal of 20045542421 is 12424554002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20019420100 + 26122321 = 141490^2 + 5111^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20045542421 is a prime.

It is a super-2 number, since 2×20045542421² (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 (20045542427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10022771210 + 10022771211.

It is an arithmetic number, because the mean of its divisors is an integer number (10022771211).

Almost surely, 2^20045542421 is an apocalyptic number.

It is an amenable number.

20045542421 is a deficient number, since it is larger than the sum of its proper divisors (1).

20045542421 is an equidigital number, since it uses as much as digits as its factorization.

20045542421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12800, while the sum is 29.

The spelling of 20045542421 in words is "twenty billion, forty-five million, five hundred forty-two thousand, four hundred twenty-one".