20342120251 has 2 divisors, whose sum is σ = 20342120252. Its totient is φ = 20342120250.

The previous prime is 20342120203. The next prime is 20342120339. The reversal of 20342120251 is 15202124302.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20342120251 - 2¹⁷ = 20341989179 is a prime.

It is a super-2 number, since 2×20342120251² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20342120951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10171060125 + 10171060126.

It is an arithmetic number, because the mean of its divisors is an integer number (10171060126).

Almost surely, 2^20342120251 is an apocalyptic number.

20342120251 is a deficient number, since it is larger than the sum of its proper divisors (1).

20342120251 is an equidigital number, since it uses as much as digits as its factorization.

20342120251 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 960, while the sum is 22.

Adding to 20342120251 its reverse (15202124302), we get a palindrome (35544244553).

The spelling of 20342120251 in words is "twenty billion, three hundred forty-two million, one hundred twenty thousand, two hundred fifty-one".