663691041 has 24 divisors (see below), whose sum is σ = 1049344296. Its totient is φ = 401725440.

The previous prime is 663691037. The next prime is 663691043. The reversal of 663691041 is 140196366.

663691041 is a `hidden beast` number, since 6 + 636 + 9 + 10 + 4 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 132158016 + 531533025 = 11496^2 + 23055^2 .

It is not a de Polignac number, because 663691041 - 2² = 663691037 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 663690987 and 663691005.

It is not an unprimeable number, because it can be changed into a prime (663691043) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 39360 + ... + 53633.

It is an arithmetic number, because the mean of its divisors is an integer number (43722679).

Almost surely, 2^663691041 is an apocalyptic number.

663691041 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

663691041 is a deficient number, since it is larger than the sum of its proper divisors (385653255).

663691041 is a wasteful number, since it uses less digits than its factorization.

663691041 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93073 (or 93070 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The square root of 663691041 is about 25762.2017886671. The cubic root of 663691041 is about 872.2788019541.

The spelling of 663691041 in words is "six hundred sixty-three million, six hundred ninety-one thousand, forty-one".