20623591987 has 2 divisors, whose sum is σ = 20623591988. Its totient is φ = 20623591986.

The previous prime is 20623591903. The next prime is 20623591993. The reversal of 20623591987 is 78919532602.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20623591987 - 2²⁷ = 20489374259 is a prime.

It is not a weakly prime, because it can be changed into another prime (20623591997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10311795993 + 10311795994.

It is an arithmetic number, because the mean of its divisors is an integer number (10311795994).

Almost surely, 2^20623591987 is an apocalyptic number.

20623591987 is a deficient number, since it is larger than the sum of its proper divisors (1).

20623591987 is an equidigital number, since it uses as much as digits as its factorization.

20623591987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1632960, while the sum is 52.

The spelling of 20623591987 in words is "twenty billion, six hundred twenty-three million, five hundred ninety-one thousand, nine hundred eighty-seven".