10646451821 has 4 divisors (see below), whose sum is σ = 10646659644. Its totient is φ = 10646244000.

The previous prime is 10646451787. The next prime is 10646451869. The reversal of 10646451821 is 12815464601.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5269162921 + 5377288900 = 72589^2 + 73330^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-10646451821 is a prime.

It is a super-2 number, since 2×10646451821² (a number of 21 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 (10646453821) 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, 33521 + ... + 149721.

It is an arithmetic number, because the mean of its divisors is an integer number (2661664911).

Almost surely, 2^10646451821 is an apocalyptic number.

It is an amenable number.

10646451821 is a deficient number, since it is larger than the sum of its proper divisors (207823).

10646451821 is an equidigital number, since it uses as much as digits as its factorization.

10646451821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207822.

The product of its (nonzero) digits is 46080, while the sum is 38.

The spelling of 10646451821 in words is "ten billion, six hundred forty-six million, four hundred fifty-one thousand, eight hundred twenty-one".