1620221015 has 24 divisors (see below), whose sum is σ = 2263574880. Its totient is φ = 1110086208.

The previous prime is 1620221011. The next prime is 1620221027. The reversal of 1620221015 is 5101220261.

It is not a de Polignac number, because 1620221015 - 2² = 1620221011 is a prime.

It is a super-2 number, since 2×1620221015² = 5250232274895260450, 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 polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 434981 + ... + 438689.

It is an arithmetic number, because the mean of its divisors is an integer number (94315620).

Almost surely, 2^1620221015 is an apocalyptic number.

1620221015 is a deficient number, since it is larger than the sum of its proper divisors (643353865).

1620221015 is a wasteful number, since it uses less digits than its factorization.

1620221015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5511 (or 5504 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 1620221015 is about 40251.9690822698. The cubic root of 1620221015 is about 1174.5137000745.

Adding to 1620221015 its reverse (5101220261), we get a palindrome (6721441276).

The spelling of 1620221015 in words is "one billion, six hundred twenty million, two hundred twenty-one thousand, fifteen".