1663341261 has 4 divisors (see below), whose sum is σ = 2217788352. Its totient is φ = 1108894172.

The previous prime is 1663341227. The next prime is 1663341269. The reversal of 1663341261 is 1621433661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1663341261 - 2¹⁷ = 1663210189 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663341269) 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, 277223541 + ... + 277223546.

It is an arithmetic number, because the mean of its divisors is an integer number (554447088).

Almost surely, 2^1663341261 is an apocalyptic number.

It is an amenable number.

1663341261 is a deficient number, since it is larger than the sum of its proper divisors (554447091).

1663341261 is an equidigital number, since it uses as much as digits as its factorization.

1663341261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 554447090.

The product of its digits is 15552, while the sum is 33.

The square root of 1663341261 is about 40784.0809753021. The cubic root of 1663341261 is about 1184.8420355942.

The spelling of 1663341261 in words is "one billion, six hundred sixty-three million, three hundred forty-one thousand, two hundred sixty-one".