663998011 has 4 divisors (see below), whose sum is σ = 664400392. Its totient is φ = 663595632.

The previous prime is 663997987. The next prime is 663998039. The reversal of 663998011 is 110899366.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 110899366 = 2 ⋅55449683.

It is a cyclic number.

It is not a de Polignac number, because 663998011 - 2¹⁷ = 663866939 is a prime.

It is a super-2 number, since 2×663998011² = 881786717223912242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (663998051) 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, 198705 + ... + 202018.

It is an arithmetic number, because the mean of its divisors is an integer number (166100098).

Almost surely, 2^663998011 is an apocalyptic number.

663998011 is a deficient number, since it is larger than the sum of its proper divisors (402381).

663998011 is a wasteful number, since it uses less digits than its factorization.

663998011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 402380.

The product of its (nonzero) digits is 69984, while the sum is 43.

The square root of 663998011 is about 25768.1588593365. The cubic root of 663998011 is about 872.4132631898.

The spelling of 663998011 in words is "six hundred sixty-three million, nine hundred ninety-eight thousand, eleven".