663506979 has 16 divisors (see below), whose sum is σ = 930700800. Its totient is φ = 419842976.

The previous prime is 663506951. The next prime is 663506989. The reversal of 663506979 is 979605366.

It is not a de Polignac number, because 663506979 - 2¹² = 663502883 is a prime.

It is a super-2 number, since 2×663506979² = 880483022363412882, which contains 22 as substring.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (663506939) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 59499 + ... + 69764.

It is an arithmetic number, because the mean of its divisors is an integer number (58168800).

Almost surely, 2^663506979 is an apocalyptic number.

663506979 is a deficient number, since it is larger than the sum of its proper divisors (267193821).

663506979 is a wasteful number, since it uses less digits than its factorization.

663506979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129354.

The product of its (nonzero) digits is 1837080, while the sum is 51.

The square root of 663506979 is about 25758.6292143041. The cubic root of 663506979 is about 872.1981578917.

The spelling of 663506979 in words is "six hundred sixty-three million, five hundred six thousand, nine hundred seventy-nine".