661563163403 has 2 divisors, whose sum is σ = 661563163404. Its totient is φ = 661563163402.

The previous prime is 661563163379. The next prime is 661563163501. The reversal of 661563163403 is 304361365166.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 661563163403 - 2²⁶ = 661496054539 is a prime.

It is not a weakly prime, because it can be changed into another prime (661563163003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330781581701 + 330781581702.

It is an arithmetic number, because the mean of its divisors is an integer number (330781581702).

Almost surely, 2^661563163403 is an apocalyptic number.

661563163403 is a deficient number, since it is larger than the sum of its proper divisors (1).

661563163403 is an equidigital number, since it uses as much as digits as its factorization.

661563163403 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 699840, while the sum is 44.

The spelling of 661563163403 in words is "six hundred sixty-one billion, five hundred sixty-three million, one hundred sixty-three thousand, four hundred three".