1620505001 has 2 divisors, whose sum is σ = 1620505002. Its totient is φ = 1620505000.

The previous prime is 1620504979. The next prime is 1620505037. The reversal of 1620505001 is 1005050261.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1565389225 + 55115776 = 39565^2 + 7424^2 .

It is a cyclic number.

It is not a de Polignac number, because 1620505001 - 2⁶ = 1620504937 is a prime.

It is not a weakly prime, because it can be changed into another prime (1620505301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810252500 + 810252501.

It is an arithmetic number, because the mean of its divisors is an integer number (810252501).

Almost surely, 2^1620505001 is an apocalyptic number.

It is an amenable number.

1620505001 is a deficient number, since it is larger than the sum of its proper divisors (1).

1620505001 is an equidigital number, since it uses as much as digits as its factorization.

1620505001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 300, while the sum is 20.

The square root of 1620505001 is about 40255.4965315297. The cubic root of 1620505001 is about 1174.5823174543.

Adding to 1620505001 its reverse (1005050261), we get a palindrome (2625555262).

The spelling of 1620505001 in words is "one billion, six hundred twenty million, five hundred five thousand, one".