1821629825 has 6 divisors (see below), whose sum is σ = 2258821014. Its totient is φ = 1457303840.

The previous prime is 1821629783. The next prime is 1821629857. The reversal of 1821629825 is 5289261281.

It can be written as a sum of positive squares in 3 ways, for example, as 2436721 + 1819193104 = 1561^2 + 42652^2 .

It is not a de Polignac number, because 1821629825 - 2⁸ = 1821629569 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 36432572 + ... + 36432621.

It is an arithmetic number, because the mean of its divisors is an integer number (376470169).

Almost surely, 2^1821629825 is an apocalyptic number.

It is an amenable number.

1821629825 is a deficient number, since it is larger than the sum of its proper divisors (437191189).

1821629825 is an equidigital number, since it uses as much as digits as its factorization.

1821629825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72865203 (or 72865198 counting only the distinct ones).

The product of its digits is 138240, while the sum is 44.

The square root of 1821629825 is about 42680.5555844813. Note that the first 4 decimals coincide. The cubic root of 1821629825 is about 1221.2934917167.

The spelling of 1821629825 in words is "one billion, eight hundred twenty-one million, six hundred twenty-nine thousand, eight hundred twenty-five".