2121199955687 has 2 divisors, whose sum is σ = 2121199955688. Its totient is φ = 2121199955686.

The previous prime is 2121199955683. The next prime is 2121199955701. The reversal of 2121199955687 is 7865599911212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2121199955687 - 2² = 2121199955683 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121199955683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060599977843 + 1060599977844.

It is an arithmetic number, because the mean of its divisors is an integer number (1060599977844).

Almost surely, 2^{2121199955687} is an apocalyptic number.

2121199955687 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121199955687 is an equidigital number, since it uses as much as digits as its factorization.

2121199955687 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24494400, while the sum is 65.

The spelling of 2121199955687 in words is "two trillion, one hundred twenty-one billion, one hundred ninety-nine million, nine hundred fifty-five thousand, six hundred eighty-seven".