2001021505 has 32 divisors (see below), whose sum is σ = 2867539968. Its totient is φ = 1310654400.

The previous prime is 2001021493. The next prime is 2001021541. The reversal of 2001021505 is 5051201002.

It is not a de Polignac number, because 2001021505 - 2⁷ = 2001021377 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 828750 + ... + 831160.

It is an arithmetic number, because the mean of its divisors is an integer number (89610624).

Almost surely, 2^2001021505 is an apocalyptic number.

It is an amenable number.

2001021505 is a deficient number, since it is larger than the sum of its proper divisors (866518463).

2001021505 is a wasteful number, since it uses less digits than its factorization.

2001021505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3477.

The product of its (nonzero) digits is 100, while the sum is 16.

The square root of 2001021505 is about 44732.7788651678. The cubic root of 2001021505 is about 1260.1355159947.

Adding to 2001021505 its reverse (5051201002), we get a palindrome (7052222507).

The spelling of 2001021505 in words is "two billion, one million, twenty-one thousand, five hundred five".