163604406503261 has 4 divisors (see below), whose sum is σ = 165291049869372. Its totient is φ = 161917763137152.

The previous prime is 163604406503231. The next prime is 163604406503267. The reversal of 163604406503261 is 162305604406361.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 37318280459161 + 126286126044100 = 6108869^2 + 11237710^2 .

It is a cyclic number.

It is not a de Polignac number, because 163604406503261 - 2¹⁴ = 163604406486877 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (163604406503267) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 843321682910 + ... + 843321683103.

It is an arithmetic number, because the mean of its divisors is an integer number (41322762467343).

Almost surely, 2^{163604406503261} is an apocalyptic number.

It is an amenable number.

163604406503261 is a deficient number, since it is larger than the sum of its proper divisors (1686643366111).

163604406503261 is an equidigital number, since it uses as much as digits as its factorization.

163604406503261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1686643366110.

The product of its (nonzero) digits is 1866240, while the sum is 47.

The spelling of 163604406503261 in words is "one hundred sixty-three trillion, six hundred four billion, four hundred six million, five hundred three thousand, two hundred sixty-one".