1621218866 has 8 divisors (see below), whose sum is σ = 2432332800. Its totient is φ = 810441268.

The previous prime is 1621218829. The next prime is 1621218941. The reversal of 1621218866 is 6688121261.

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

It is a super-2 number, since 2×1621218866² = 5256701222948651912, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71666 + ... + 91533.

It is an arithmetic number, because the mean of its divisors is an integer number (304041600).

Almost surely, 2^1621218866 is an apocalyptic number.

1621218866 is a deficient number, since it is larger than the sum of its proper divisors (811113934).

1621218866 is a wasteful number, since it uses less digits than its factorization.

1621218866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168168.

The product of its digits is 55296, while the sum is 41.

The square root of 1621218866 is about 40264.3622326245. The cubic root of 1621218866 is about 1174.7547678347.

The spelling of 1621218866 in words is "one billion, six hundred twenty-one million, two hundred eighteen thousand, eight hundred sixty-six".