1620221013 has 6 divisors (see below), whose sum is σ = 2340319254. Its totient is φ = 1080147336.

The previous prime is 1620221011. The next prime is 1620221027. The reversal of 1620221013 is 3101220261.

1620221013 is a `hidden beast` number, since 1 + 620 + 22 + 10 + 13 = 666.

It can be written as a sum of positive squares in only one way, i.e., 998117649 + 622103364 = 31593^2 + 24942^2 .

It is not a de Polignac number, because 1620221013 - 2¹ = 1620221011 is a prime.

It is a super-2 number, since 2×1620221013² = 5250232261933492338, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1620221011) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 90012270 + ... + 90012287.

It is an arithmetic number, because the mean of its divisors is an integer number (390053209).

Almost surely, 2^1620221013 is an apocalyptic number.

It is an amenable number.

1620221013 is a deficient number, since it is larger than the sum of its proper divisors (720098241).

1620221013 is a wasteful number, since it uses less digits than its factorization.

1620221013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180024563 (or 180024560 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 1620221013 is about 40251.9690574262. The cubic root of 1620221013 is about 1174.5136995912.

Adding to 1620221013 its reverse (3101220261), we get a palindrome (4721441274).

The spelling of 1620221013 in words is "one billion, six hundred twenty million, two hundred twenty-one thousand, thirteen".