1672219821 has 4 divisors (see below), whose sum is σ = 2229626432. Its totient is φ = 1114813212.

The previous prime is 1672219817. The next prime is 1672219859. The reversal of 1672219821 is 1289122761.

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 1672219821 - 2² = 1672219817 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 1672219821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1672219121) 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, 278703301 + ... + 278703306.

It is an arithmetic number, because the mean of its divisors is an integer number (557406608).

Almost surely, 2^1672219821 is an apocalyptic number.

It is an amenable number.

1672219821 is a deficient number, since it is larger than the sum of its proper divisors (557406611).

1672219821 is an equidigital number, since it uses as much as digits as its factorization.

1672219821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 557406610.

The product of its digits is 24192, while the sum is 39.

The square root of 1672219821 is about 40892.7844613203. The cubic root of 1672219821 is about 1186.9464402186.

The spelling of 1672219821 in words is "one billion, six hundred seventy-two million, two hundred nineteen thousand, eight hundred twenty-one".