20021100110251 has 2 divisors, whose sum is σ = 20021100110252. Its totient is φ = 20021100110250.

The previous prime is 20021100110243. The next prime is 20021100110261. The reversal of 20021100110251 is 15201100112002.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20021100110251 - 2³ = 20021100110243 is a prime.

It is not a weakly prime, because it can be changed into another prime (20021100110261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10010550055125 + 10010550055126.

It is an arithmetic number, because the mean of its divisors is an integer number (10010550055126).

Almost surely, 2^{20021100110251} is an apocalyptic number.

20021100110251 is a deficient number, since it is larger than the sum of its proper divisors (1).

20021100110251 is an equidigital number, since it uses as much as digits as its factorization.

20021100110251 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40, while the sum is 16.

Adding to 20021100110251 its reverse (15201100112002), we get a palindrome (35222200222253).

The spelling of 20021100110251 in words is "twenty trillion, twenty-one billion, one hundred million, one hundred ten thousand, two hundred fifty-one".