2001215251 has 4 divisors (see below), whose sum is σ = 2287103152. Its totient is φ = 1715327352.

The previous prime is 2001215221. The next prime is 2001215309. The reversal of 2001215251 is 1525121002.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1525121002 = 2 ⋅762560501.

It is a cyclic number.

It is not a de Polignac number, because 2001215251 - 2¹³ = 2001207059 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2001215201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 142943940 + ... + 142943953.

It is an arithmetic number, because the mean of its divisors is an integer number (571775788).

Almost surely, 2^2001215251 is an apocalyptic number.

2001215251 is a deficient number, since it is larger than the sum of its proper divisors (285887901).

2001215251 is an equidigital number, since it uses as much as digits as its factorization.

2001215251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285887900.

The product of its (nonzero) digits is 200, while the sum is 19.

The square root of 2001215251 is about 44734.9444059116. The cubic root of 2001215251 is about 1260.1761849456.

Adding to 2001215251 its reverse (1525121002), we get a palindrome (3526336253).

The spelling of 2001215251 in words is "two billion, one million, two hundred fifteen thousand, two hundred fifty-one".