121431591539989 has 2 divisors, whose sum is σ = 121431591539990. Its totient is φ = 121431591539988.

The previous prime is 121431591539981. The next prime is 121431591540023. The reversal of 121431591539989 is 989935195134121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 89871442803025 + 31560148736964 = 9480055^2 + 5617842^2 .

It is a cyclic number.

It is not a de Polignac number, because 121431591539989 - 2³ = 121431591539981 is a prime.

It is a super-2 number, since 2×121431591539989² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121431591539981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60715795769994 + 60715795769995.

It is an arithmetic number, because the mean of its divisors is an integer number (60715795769995).

Almost surely, 2^{121431591539989} is an apocalyptic number.

It is an amenable number.

121431591539989 is a deficient number, since it is larger than the sum of its proper divisors (1).

121431591539989 is an equidigital number, since it uses as much as digits as its factorization.

121431591539989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 94478400, while the sum is 70.

The spelling of 121431591539989 in words is "one hundred twenty-one trillion, four hundred thirty-one billion, five hundred ninety-one million, five hundred thirty-nine thousand, nine hundred eighty-nine".