21837187499 has 2 divisors, whose sum is σ = 21837187500. Its totient is φ = 21837187498.

The previous prime is 21837187451. The next prime is 21837187501. The reversal of 21837187499 is 99478173812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21837187499 - 2³² = 17542220203 is a prime.

Together with 21837187501, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21837187409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10918593749 + 10918593750.

It is an arithmetic number, because the mean of its divisors is an integer number (10918593750).

Almost surely, 2^21837187499 is an apocalyptic number.

21837187499 is a deficient number, since it is larger than the sum of its proper divisors (1).

21837187499 is an equidigital number, since it uses as much as digits as its factorization.

21837187499 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6096384, while the sum is 59.

The spelling of 21837187499 in words is "twenty-one billion, eight hundred thirty-seven million, one hundred eighty-seven thousand, four hundred ninety-nine".