121211531021531 has 2 divisors, whose sum is σ = 121211531021532. Its totient is φ = 121211531021530.

The previous prime is 121211531021507. The next prime is 121211531021663. The reversal of 121211531021531 is 135120135112121.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 121211531021531 - 2⁶ = 121211531021467 is a prime.

It is a super-2 number, since 2×121211531021531² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 121211531021494 and 121211531021503.

It is not a weakly prime, because it can be changed into another prime (121211531021131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60605765510765 + 60605765510766.

It is an arithmetic number, because the mean of its divisors is an integer number (60605765510766).

Almost surely, 2^{121211531021531} is an apocalyptic number.

121211531021531 is a deficient number, since it is larger than the sum of its proper divisors (1).

121211531021531 is an equidigital number, since it uses as much as digits as its factorization.

121211531021531 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1800, while the sum is 29.

Adding to 121211531021531 its reverse (135120135112121), we get a palindrome (256331666133652).

The spelling of 121211531021531 in words is "one hundred twenty-one trillion, two hundred eleven billion, five hundred thirty-one million, twenty-one thousand, five hundred thirty-one".