660887638 has 4 divisors (see below), whose sum is σ = 991331460. Its totient is φ = 330443818.

The previous prime is 660887627. The next prime is 660887657. The reversal of 660887638 is 836788066.

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

It is a super-2 number, since 2×660887638² = 873544940122438088, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165221908 + ... + 165221911.

It is an arithmetic number, because the mean of its divisors is an integer number (247832865).

Almost surely, 2^660887638 is an apocalyptic number.

660887638 is a deficient number, since it is larger than the sum of its proper divisors (330443822).

660887638 is a wasteful number, since it uses less digits than its factorization.

660887638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 330443821.

The product of its (nonzero) digits is 2322432, while the sum is 52.

The square root of 660887638 is about 25707.7349838526. The cubic root of 660887638 is about 871.0489123527.

The spelling of 660887638 in words is "six hundred sixty million, eight hundred eighty-seven thousand, six hundred thirty-eight".