660398654 has 4 divisors (see below), whose sum is σ = 990597984. Its totient is φ = 330199326.

The previous prime is 660398653. The next prime is 660398659. The reversal of 660398654 is 456893066.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×660398654² = 872252764410023432, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 660398599 and 660398608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660398653) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165099662 + ... + 165099665.

It is an arithmetic number, because the mean of its divisors is an integer number (247649496).

Almost surely, 2^660398654 is an apocalyptic number.

660398654 is a deficient number, since it is larger than the sum of its proper divisors (330199330).

660398654 is a wasteful number, since it uses less digits than its factorization.

660398654 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330199329.

The product of its (nonzero) digits is 933120, while the sum is 47.

The square root of 660398654 is about 25698.2227790172. Note that the first 3 decimals coincide. The cubic root of 660398654 is about 870.8340326228.

The spelling of 660398654 in words is "six hundred sixty million, three hundred ninety-eight thousand, six hundred fifty-four".