2121640236431 has 2 divisors, whose sum is σ = 2121640236432. Its totient is φ = 2121640236430.

The previous prime is 2121640236409. The next prime is 2121640236451. The reversal of 2121640236431 is 1346320461212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2121640236431 - 2²⁶ = 2121573127567 is a prime.

It is a super-2 number, since 2×2121640236431² (a number of 25 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 2121640236391 and 2121640236400.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121640236451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060820118215 + 1060820118216.

It is an arithmetic number, because the mean of its divisors is an integer number (1060820118216).

Almost surely, 2^{2121640236431} is an apocalyptic number.

2121640236431 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121640236431 is an equidigital number, since it uses as much as digits as its factorization.

2121640236431 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 35.

Adding to 2121640236431 its reverse (1346320461212), we get a palindrome (3467960697643).

The spelling of 2121640236431 in words is "two trillion, one hundred twenty-one billion, six hundred forty million, two hundred thirty-six thousand, four hundred thirty-one".