3261628728781 has 4 divisors (see below), whose sum is σ = 3271028235552. Its totient is φ = 3252229222012.

The previous prime is 3261628728707. The next prime is 3261628728797. The reversal of 3261628728781 is 1878278261623.

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.

It is a cyclic number.

It is not a de Polignac number, because 3261628728781 - 2⁹ = 3261628728269 is a prime.

It is a super-2 number, since 2×3261628728781² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3261628726781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4699752865 + ... + 4699753558.

It is an arithmetic number, because the mean of its divisors is an integer number (817757058888).

Almost surely, 2^{3261628728781} is an apocalyptic number.

It is an amenable number.

3261628728781 is a deficient number, since it is larger than the sum of its proper divisors (9399506771).

3261628728781 is an equidigital number, since it uses as much as digits as its factorization.

3261628728781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9399506770.

The product of its digits is 21676032, while the sum is 61.

The spelling of 3261628728781 in words is "three trillion, two hundred sixty-one billion, six hundred twenty-eight million, seven hundred twenty-eight thousand, seven hundred eighty-one".