1821686722 has 8 divisors (see below), whose sum is σ = 2733437772. Its totient is φ = 910540800.

The previous prime is 1821686609. The next prime is 1821686729. The reversal of 1821686722 is 2276861281.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1324887201 + 496799521 = 36399^2 + 22289^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×1821686722² = 6637085026222210568, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1821686729) 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, 143679 + ... + 155842.

Almost surely, 2^1821686722 is an apocalyptic number.

1821686722 is a deficient number, since it is larger than the sum of its proper divisors (911751050).

1821686722 is a wasteful number, since it uses less digits than its factorization.

1821686722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 302564.

The product of its digits is 129024, while the sum is 43.

The square root of 1821686722 is about 42681.2221240208. Note that the first 3 decimals coincide. The cubic root of 1821686722 is about 1221.3062069258.

The spelling of 1821686722 in words is "one billion, eight hundred twenty-one million, six hundred eighty-six thousand, seven hundred twenty-two".