2002621681 has 4 divisors (see below), whose sum is σ = 2002727664. Its totient is φ = 2002515700.

The previous prime is 2002621667. The next prime is 2002621721. The reversal of 2002621681 is 1861262002.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 2002621681 - 2⁹ = 2002621169 is a prime.

It is a super-2 number, since 2×2002621681² = 8020987194422531522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2002621631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16075 + ... + 65296.

It is an arithmetic number, because the mean of its divisors is an integer number (500681916).

Almost surely, 2^2002621681 is an apocalyptic number.

It is an amenable number.

2002621681 is a deficient number, since it is larger than the sum of its proper divisors (105983).

2002621681 is an equidigital number, since it uses as much as digits as its factorization.

2002621681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105982.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 2002621681 is about 44750.6612353382. The cubic root of 2002621681 is about 1260.4713280356.

Adding to 2002621681 its reverse (1861262002), we get a palindrome (3863883683).

The spelling of 2002621681 in words is "two billion, two million, six hundred twenty-one thousand, six hundred eighty-one".