1821679201 has 4 divisors (see below), whose sum is σ = 1870913812. Its totient is φ = 1772444592.

The previous prime is 1821679187. The next prime is 1821679213. The reversal of 1821679201 is 1029761281.

It is the 17425-th star number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1029761281 = 17 ⋅60574193.

It can be written as a sum of positive squares in 2 ways, for example, as 1009714176 + 811965025 = 31776^2 + 28495^2 .

It is a cyclic number.

It is not a de Polignac number, because 1821679201 - 2⁹ = 1821678689 is a prime.

It is a super-2 number, since 2×1821679201² = 6637030222711996802, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37), and also a Moran number because the ratio is a prime number: 49234573 = 1821679201 / (1 + 8 + 2 + 1 + 6 + 7 + 9 + 2 + 0 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1821679901) 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, 24617250 + ... + 24617323.

It is an arithmetic number, because the mean of its divisors is an integer number (467728453).

Almost surely, 2^1821679201 is an apocalyptic number.

It is an amenable number.

1821679201 is a deficient number, since it is larger than the sum of its proper divisors (49234611).

1821679201 is an equidigital number, since it uses as much as digits as its factorization.

1821679201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49234610.

The product of its (nonzero) digits is 12096, while the sum is 37.

The square root of 1821679201 is about 42681.1340172681. The cubic root of 1821679201 is about 1221.3045261655.

The spelling of 1821679201 in words is "one billion, eight hundred twenty-one million, six hundred seventy-nine thousand, two hundred one".