1321634664 has 192 divisors, whose sum is σ = 4299350400. Its totient is φ = 375072768.

The previous prime is 1321634663. The next prime is 1321634729. The reversal of 1321634664 is 4664361231.

1321634664 is a `hidden beast` number, since 1 + 32 + 163 + 466 + 4 = 666.

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

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (1321634663) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2042389 + ... + 2043035.

It is an arithmetic number, because the mean of its divisors is an integer number (22392450).

Almost surely, 2^1321634664 is an apocalyptic number.

1321634664 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1321634664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2149675200).

1321634664 is an abundant number, since it is smaller than the sum of its proper divisors (2977715736).

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

1321634664 is a wasteful number, since it uses less digits than its factorization.

1321634664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 869 (or 852 counting only the distinct ones).

The product of its digits is 62208, while the sum is 36.

The square root of 1321634664 is about 36354.2936116217. The cubic root of 1321634664 is about 1097.4139426748.

Adding to 1321634664 its reverse (4664361231), we get a palindrome (5985995895).

The spelling of 1321634664 in words is "one billion, three hundred twenty-one million, six hundred thirty-four thousand, six hundred sixty-four".