20415531112121 has 2 divisors, whose sum is σ = 20415531112122. Its totient is φ = 20415531112120.

The previous prime is 20415531112117. The next prime is 20415531112147. The reversal of 20415531112121 is 12121113551402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12601158135721 + 7814372976400 = 3549811^2 + 2795420^2 .

It is a cyclic number.

It is not a de Polignac number, because 20415531112121 - 2² = 20415531112117 is a prime.

It is not a weakly prime, because it can be changed into another prime (20415531112421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10207765556060 + 10207765556061.

It is an arithmetic number, because the mean of its divisors is an integer number (10207765556061).

Almost surely, 2^{20415531112121} is an apocalyptic number.

It is an amenable number.

20415531112121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20415531112121 is an equidigital number, since it uses as much as digits as its factorization.

20415531112121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2400, while the sum is 29.

Adding to 20415531112121 its reverse (12121113551402), we get a palindrome (32536644663523).

The spelling of 20415531112121 in words is "twenty trillion, four hundred fifteen billion, five hundred thirty-one million, one hundred twelve thousand, one hundred twenty-one".