20646135487 has 2 divisors, whose sum is σ = 20646135488. Its totient is φ = 20646135486.

The previous prime is 20646135409. The next prime is 20646135527. The reversal of 20646135487 is 78453164602.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20646135487 - 2²⁷ = 20511917759 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20646135787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10323067743 + 10323067744.

It is an arithmetic number, because the mean of its divisors is an integer number (10323067744).

Almost surely, 2^20646135487 is an apocalyptic number.

20646135487 is a deficient number, since it is larger than the sum of its proper divisors (1).

20646135487 is an equidigital number, since it uses as much as digits as its factorization.

20646135487 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 967680, while the sum is 46.

The spelling of 20646135487 in words is "twenty billion, six hundred forty-six million, one hundred thirty-five thousand, four hundred eighty-seven".