4345561821 has 4 divisors (see below), whose sum is σ = 5794082432. Its totient is φ = 2897041212.

The previous prime is 4345561819. The next prime is 4345561889. The reversal of 4345561821 is 1281655434.

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 not a de Polignac number, because 4345561821 - 2¹ = 4345561819 is a prime.

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 4345561821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4345561321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 724260301 + ... + 724260306.

It is an arithmetic number, because the mean of its divisors is an integer number (1448520608).

Almost surely, 2^4345561821 is an apocalyptic number.

It is an amenable number.

4345561821 is a deficient number, since it is larger than the sum of its proper divisors (1448520611).

4345561821 is a wasteful number, since it uses less digits than its factorization.

4345561821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1448520610.

The product of its digits is 115200, while the sum is 39.

The square root of 4345561821 is about 65920.8754568687. The cubic root of 4345561821 is about 1631.8565445890.

The spelling of 4345561821 in words is "four billion, three hundred forty-five million, five hundred sixty-one thousand, eight hundred twenty-one".