20021122157 has 2 divisors, whose sum is σ = 20021122158. Its totient is φ = 20021122156.

The previous prime is 20021122097. The next prime is 20021122159. The reversal of 20021122157 is 75122112002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10058886436 + 9962235721 = 100294^2 + 99811^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20021122157 is a prime.

Together with 20021122159, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20021122159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10010561078 + 10010561079.

It is an arithmetic number, because the mean of its divisors is an integer number (10010561079).

Almost surely, 2^20021122157 is an apocalyptic number.

It is an amenable number.

20021122157 is a deficient number, since it is larger than the sum of its proper divisors (1).

20021122157 is an equidigital number, since it uses as much as digits as its factorization.

20021122157 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 560, while the sum is 23.

Adding to 20021122157 its reverse (75122112002), we get a palindrome (95143234159).

The spelling of 20021122157 in words is "twenty billion, twenty-one million, one hundred twenty-two thousand, one hundred fifty-seven".