20506449659 has 2 divisors, whose sum is σ = 20506449660. Its totient is φ = 20506449658.

The previous prime is 20506449629. The next prime is 20506449703. The reversal of 20506449659 is 95694460502.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20506449659 - 2¹⁶ = 20506384123 is a prime.

It is a super-4 number, since 4×20506449659⁴ (a number of 42 digits) contains 4444 as substring.

It is not a weakly prime, because it can be changed into another prime (20506449629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10253224829 + 10253224830.

It is an arithmetic number, because the mean of its divisors is an integer number (10253224830).

Almost surely, 2^20506449659 is an apocalyptic number.

20506449659 is a deficient number, since it is larger than the sum of its proper divisors (1).

20506449659 is an equidigital number, since it uses as much as digits as its factorization.

20506449659 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2332800, while the sum is 50.

The spelling of 20506449659 in words is "twenty billion, five hundred six million, four hundred forty-nine thousand, six hundred fifty-nine".