20742578663 has 2 divisors, whose sum is σ = 20742578664. Its totient is φ = 20742578662.

The previous prime is 20742578651. The next prime is 20742578707. The reversal of 20742578663 is 36687524702.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20742578663 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20742578063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10371289331 + 10371289332.

It is an arithmetic number, because the mean of its divisors is an integer number (10371289332).

Almost surely, 2^20742578663 is an apocalyptic number.

20742578663 is a deficient number, since it is larger than the sum of its proper divisors (1).

20742578663 is an equidigital number, since it uses as much as digits as its factorization.

20742578663 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3386880, while the sum is 50.

The spelling of 20742578663 in words is "twenty billion, seven hundred forty-two million, five hundred seventy-eight thousand, six hundred sixty-three".