20023121257 has 2 divisors, whose sum is σ = 20023121258. Its totient is φ = 20023121256.

The previous prime is 20023121233. The next prime is 20023121297. The reversal of 20023121257 is 75212132002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19288765456 + 734355801 = 138884^2 + 27099^2 .

It is a cyclic number.

It is not a de Polignac number, because 20023121257 - 2²³ = 20014732649 is a prime.

It is a super-3 number, since 3×20023121257³ (a number of 32 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (20023121227) 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, 10011560628 + 10011560629.

It is an arithmetic number, because the mean of its divisors is an integer number (10011560629).

Almost surely, 2^20023121257 is an apocalyptic number.

It is an amenable number.

20023121257 is a deficient number, since it is larger than the sum of its proper divisors (1).

20023121257 is an equidigital number, since it uses as much as digits as its factorization.

20023121257 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1680, while the sum is 25.

Adding to 20023121257 its reverse (75212132002), we get a palindrome (95235253259).

The spelling of 20023121257 in words is "twenty billion, twenty-three million, one hundred twenty-one thousand, two hundred fifty-seven".