20661366063 has 16 divisors (see below), whose sum is σ = 30469431776. Its totient is φ = 12371045760.

The previous prime is 20661366031. The next prime is 20661366073. The reversal of 20661366063 is 36066316602.

It is a happy number.

It is not a de Polignac number, because 20661366063 - 2⁵ = 20661366031 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20661366073) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7157728 + ... + 7160613.

It is an arithmetic number, because the mean of its divisors is an integer number (1904339486).

Almost surely, 2^20661366063 is an apocalyptic number.

20661366063 is a deficient number, since it is larger than the sum of its proper divisors (9808065713).

20661366063 is a wasteful number, since it uses less digits than its factorization.

20661366063 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14318394.

The product of its (nonzero) digits is 139968, while the sum is 39.

The spelling of 20661366063 in words is "twenty billion, six hundred sixty-one million, three hundred sixty-six thousand, sixty-three".