26664619987 has 2 divisors, whose sum is σ = 26664619988. Its totient is φ = 26664619986.

The previous prime is 26664619979. The next prime is 26664620033. The reversal of 26664619987 is 78991646662.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 26664619987 - 2³ = 26664619979 is a prime.

It is a super-2 number, since 2×26664619987² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (26664614987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13332309993 + 13332309994.

It is an arithmetic number, because the mean of its divisors is an integer number (13332309994).

Almost surely, 2^26664619987 is an apocalyptic number.

26664619987 is a deficient number, since it is larger than the sum of its proper divisors (1).

26664619987 is an equidigital number, since it uses as much as digits as its factorization.

26664619987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 47029248, while the sum is 64.

The spelling of 26664619987 in words is "twenty-six billion, six hundred sixty-four million, six hundred nineteen thousand, nine hundred eighty-seven".