1620221001 has 32 divisors (see below), whose sum is σ = 2510773248. Its totient is φ = 910198080.

The previous prime is 1620220999. The next prime is 1620221011. The reversal of 1620221001 is 1001220261.

It is not a de Polignac number, because 1620221001 - 2¹ = 1620220999 is a prime.

It is a Curzon 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 31 ways as a sum of consecutive naturals, for example, 1030546 + ... + 1032116.

It is an arithmetic number, because the mean of its divisors is an integer number (78461664).

Almost surely, 2^1620221001 is an apocalyptic number.

It is an amenable number.

1620221001 is a deficient number, since it is larger than the sum of its proper divisors (890552247).

1620221001 is a wasteful number, since it uses less digits than its factorization.

1620221001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2381.

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 1620221001 is about 40251.9689083652. The cubic root of 1620221001 is about 1174.5136966916.

Adding to 1620221001 its reverse (1001220261), we get a palindrome (2621441262).

The spelling of 1620221001 in words is "one billion, six hundred twenty million, two hundred twenty-one thousand, one".