1620017979901 has 4 divisors (see below), whose sum is σ = 1620020811292. Its totient is φ = 1620015148512.

The previous prime is 1620017979883. The next prime is 1620017979907. The reversal of 1620017979901 is 1099797100261.

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

It can be written as a sum of positive squares in 2 ways, for example, as 709386747001 + 910631232900 = 842251^2 + 954270^2 .

It is a cyclic number.

It is not a de Polignac number, because 1620017979901 - 2⁹ = 1620017979389 is a prime.

It is a super-3 number, since 3×1620017979901³ (a number of 38 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1620017979907) 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, 221880 + ... + 1813633.

It is an arithmetic number, because the mean of its divisors is an integer number (405005202823).

Almost surely, 2^{1620017979901} is an apocalyptic number.

It is an amenable number.

1620017979901 is a deficient number, since it is larger than the sum of its proper divisors (2831391).

1620017979901 is an equidigital number, since it uses as much as digits as its factorization.

1620017979901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2831390.

The product of its (nonzero) digits is 428652, while the sum is 52.

The spelling of 1620017979901 in words is "one trillion, six hundred twenty billion, seventeen million, nine hundred seventy-nine thousand, nine hundred one".