1621664665179 has 16 divisors (see below), whose sum is σ = 2344171956000. Its totient is φ = 991249848576.

The previous prime is 1621664665171. The next prime is 1621664665217. The reversal of 1621664665179 is 9715664661261.

It is not a de Polignac number, because 1621664665179 - 2³ = 1621664665171 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1621664665171) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 139528234 + ... + 139539855.

It is an arithmetic number, because the mean of its divisors is an integer number (146510747250).

Almost surely, 2^{1621664665179} is an apocalyptic number.

1621664665179 is a deficient number, since it is larger than the sum of its proper divisors (722507290821).

1621664665179 is a wasteful number, since it uses less digits than its factorization.

1621664665179 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 279068254.

The product of its digits is 19595520, while the sum is 60.

The spelling of 1621664665179 in words is "one trillion, six hundred twenty-one billion, six hundred sixty-four million, six hundred sixty-five thousand, one hundred seventy-nine".