33645684821 has 12 divisors (see below), whose sum is σ = 40196666988. Its totient is φ = 28059720192.

The previous prime is 33645684817. The next prime is 33645684847. The reversal of 33645684821 is 12848654633.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 16271808721 + 17373876100 = 127561^2 + 131810^2 .

It is not a de Polignac number, because 33645684821 - 2² = 33645684817 is a prime.

It is a super-2 number, since 2×33645684821² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 33645684821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (33645684811) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9277196 + ... + 9280821.

It is an arithmetic number, because the mean of its divisors is an integer number (3349722249).

Almost surely, 2^33645684821 is an apocalyptic number.

It is an amenable number.

33645684821 is a deficient number, since it is larger than the sum of its proper divisors (6550982167).

33645684821 is a wasteful number, since it uses less digits than its factorization.

33645684821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18558068 (or 18558061 counting only the distinct ones).

The product of its digits is 3317760, while the sum is 50.

The spelling of 33645684821 in words is "thirty-three billion, six hundred forty-five million, six hundred eighty-four thousand, eight hundred twenty-one".