20987647948759 has 2 divisors, whose sum is σ = 20987647948760. Its totient is φ = 20987647948758.

The previous prime is 20987647948747. The next prime is 20987647948831. The reversal of 20987647948759 is 95784974678902.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20987647948759 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20987647948159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10493823974379 + 10493823974380.

It is an arithmetic number, because the mean of its divisors is an integer number (10493823974380).

Almost surely, 2^{20987647948759} is an apocalyptic number.

20987647948759 is a deficient number, since it is larger than the sum of its proper divisors (1).

20987647948759 is an equidigital number, since it uses as much as digits as its factorization.

20987647948759 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15362887680, while the sum is 85.

It can be divided in two parts, 20987 and 647948759, that added together give a palindrome (647969746).

The spelling of 20987647948759 in words is "twenty trillion, nine hundred eighty-seven billion, six hundred forty-seven million, nine hundred forty-eight thousand, seven hundred fifty-nine".