663667541 has 4 divisors (see below), whose sum is σ = 663835500. Its totient is φ = 663499584.

The previous prime is 663667517. The next prime is 663667559. The reversal of 663667541 is 145766366.

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 260822500 + 402845041 = 16150^2 + 20071^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-663667541 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 663667492 and 663667501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663667141) 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, 77906 + ... + 86003.

It is an arithmetic number, because the mean of its divisors is an integer number (165958875).

Almost surely, 2^663667541 is an apocalyptic number.

It is an amenable number.

663667541 is a deficient number, since it is larger than the sum of its proper divisors (167959).

663667541 is a wasteful number, since it uses less digits than its factorization.

663667541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167958.

The product of its digits is 544320, while the sum is 44.

The square root of 663667541 is about 25761.7456900731. The cubic root of 663667541 is about 872.2685066046.

The spelling of 663667541 in words is "six hundred sixty-three million, six hundred sixty-seven thousand, five hundred forty-one".