311660021 has 8 divisors (see below), whose sum is σ = 328342080. Its totient is φ = 295005888.

The previous prime is 311660017. The next prime is 311660039. The reversal of 311660021 is 120066113.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 311660021 - 2² = 311660017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 311659975 and 311660002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (311660521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18320 + ... + 30966.

It is an arithmetic number, because the mean of its divisors is an integer number (41042760).

Almost surely, 2^311660021 is an apocalyptic number.

It is an amenable number.

311660021 is a deficient number, since it is larger than the sum of its proper divisors (16682059).

311660021 is a wasteful number, since it uses less digits than its factorization.

311660021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13963.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 311660021 is about 17653.8953491857. The cubic root of 311660021 is about 677.9958442212.

The spelling of 311660021 in words is "three hundred eleven million, six hundred sixty thousand, twenty-one".