1821662064 has 120 divisors (see below), whose sum is σ = 5448334320. Its totient is φ = 566175744.

The previous prime is 1821662041. The next prime is 1821662071. The reversal of 1821662064 is 4602661281.

1821662064 is a `hidden beast` number, since 1 + 8 + 21 + 6 + 620 + 6 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 263419 + ... + 270245.

It is an arithmetic number, because the mean of its divisors is an integer number (45402786).

Almost surely, 2^1821662064 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1821662064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2724167160).

1821662064 is an abundant number, since it is smaller than the sum of its proper divisors (3626672256).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1821662064 is a wasteful number, since it uses less digits than its factorization.

1821662064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6967 (or 6958 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 1821662064 is about 42680.9332606493. The cubic root of 1821662064 is about 1221.3006964459.

The spelling of 1821662064 in words is "one billion, eight hundred twenty-one million, six hundred sixty-two thousand, sixty-four".