660698881 has 4 divisors (see below), whose sum is σ = 674756352. Its totient is φ = 646641412.

The previous prime is 660698879. The next prime is 660698891. The reversal of 660698881 is 188896066.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 660698881 - 2¹ = 660698879 is a prime.

It is a super-2 number, since 2×660698881² = 873046022709304322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (660698891) 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, 7028665 + ... + 7028758.

It is an arithmetic number, because the mean of its divisors is an integer number (168689088).

Almost surely, 2^660698881 is an apocalyptic number.

It is an amenable number.

660698881 is a deficient number, since it is larger than the sum of its proper divisors (14057471).

660698881 is a wasteful number, since it uses less digits than its factorization.

660698881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14057470.

The product of its (nonzero) digits is 995328, while the sum is 52.

The square root of 660698881 is about 25704.0635114373. The cubic root of 660698881 is about 870.9659773092.

The spelling of 660698881 in words is "six hundred sixty million, six hundred ninety-eight thousand, eight hundred eighty-one".