20436630989 has 2 divisors, whose sum is σ = 20436630990. Its totient is φ = 20436630988.

The previous prime is 20436630961. The next prime is 20436631001. The reversal of 20436630989 is 98903663402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18645902500 + 1790728489 = 136550^2 + 42317^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20436630989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20436630959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10218315494 + 10218315495.

It is an arithmetic number, because the mean of its divisors is an integer number (10218315495).

Almost surely, 2^20436630989 is an apocalyptic number.

It is an amenable number.

20436630989 is a deficient number, since it is larger than the sum of its proper divisors (1).

20436630989 is an equidigital number, since it uses as much as digits as its factorization.

20436630989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1679616, while the sum is 50.

The spelling of 20436630989 in words is "twenty billion, four hundred thirty-six million, six hundred thirty thousand, nine hundred eighty-nine".