21020220122087 has 2 divisors, whose sum is σ = 21020220122088. Its totient is φ = 21020220122086.

The previous prime is 21020220122039. The next prime is 21020220122137. The reversal of 21020220122087 is 78022102202012.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21020220122087 - 2¹⁶ = 21020220056551 is a prime.

It is a super-3 number, since 3×21020220122087³ (a number of 41 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21020220122287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510110061043 + 10510110061044.

It is an arithmetic number, because the mean of its divisors is an integer number (10510110061044).

Almost surely, 2^{21020220122087} is an apocalyptic number.

21020220122087 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020220122087 is an equidigital number, since it uses as much as digits as its factorization.

21020220122087 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3584, while the sum is 29.

Adding to 21020220122087 its reverse (78022102202012), we get a palindrome (99042322324099).

The spelling of 21020220122087 in words is "twenty-one trillion, twenty billion, two hundred twenty million, one hundred twenty-two thousand, eighty-seven".