21999196787 has 2 divisors, whose sum is σ = 21999196788. Its totient is φ = 21999196786.

The previous prime is 21999196763. The next prime is 21999196801. The reversal of 21999196787 is 78769199912.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21999196787 is a prime.

It is a super-2 number, since 2×21999196787² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21999196727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10999598393 + 10999598394.

It is an arithmetic number, because the mean of its divisors is an integer number (10999598394).

Almost surely, 2^21999196787 is an apocalyptic number.

21999196787 is a deficient number, since it is larger than the sum of its proper divisors (1).

21999196787 is an equidigital number, since it uses as much as digits as its factorization.

21999196787 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30862944, while the sum is 68.

The spelling of 21999196787 in words is "twenty-one billion, nine hundred ninety-nine million, one hundred ninety-six thousand, seven hundred eighty-seven".