2121640236389 has 2 divisors, whose sum is σ = 2121640236390. Its totient is φ = 2121640236388.

The previous prime is 2121640236337. The next prime is 2121640236409. The reversal of 2121640236389 is 9836320461212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2106402309025 + 15237927364 = 1451345^2 + 123442^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121640236389 - 2³² = 2117345269093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121640236329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060820118194 + 1060820118195.

It is an arithmetic number, because the mean of its divisors is an integer number (1060820118195).

Almost surely, 2^{2121640236389} is an apocalyptic number.

It is an amenable number.

2121640236389 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121640236389 is an equidigital number, since it uses as much as digits as its factorization.

2121640236389 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 746496, while the sum is 47.

The spelling of 2121640236389 in words is "two trillion, one hundred twenty-one billion, six hundred forty million, two hundred thirty-six thousand, three hundred eighty-nine".