20438240287 has 2 divisors, whose sum is σ = 20438240288. Its totient is φ = 20438240286.

The previous prime is 20438240213. The next prime is 20438240299. The reversal of 20438240287 is 78204283402.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20438240287 - 2⁷ = 20438240159 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20438240687) 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, 10219120143 + 10219120144.

It is an arithmetic number, because the mean of its divisors is an integer number (10219120144).

Almost surely, 2^20438240287 is an apocalyptic number.

20438240287 is a deficient number, since it is larger than the sum of its proper divisors (1).

20438240287 is an equidigital number, since it uses as much as digits as its factorization.

20438240287 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 172032, while the sum is 40.

The spelling of 20438240287 in words is "twenty billion, four hundred thirty-eight million, two hundred forty thousand, two hundred eighty-seven".