1321606400 has 54 divisors (see below), whose sum is σ = 3271198182. Its totient is φ = 528640000.

The previous prime is 1321606397. The next prime is 1321606417. The reversal of 1321606400 is 46061231.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 291453184 + 1030153216 = 17072^2 + 32096^2 .

It is a congruent 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, 96851 + ... + 109650.

Almost surely, 2^1321606400 is an apocalyptic number.

1321606400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1321606400 is an abundant number, since it is smaller than the sum of its proper divisors (1949591782).

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

1321606400 is an equidigital number, since it uses as much as digits as its factorization.

1321606400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206527 (or 206508 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 1321606400 is about 36353.9048796687. The cubic root of 1321606400 is about 1097.4061196534.

Adding to 1321606400 its reverse (46061231), we get a palindrome (1367667631).

The spelling of 1321606400 in words is "one billion, three hundred twenty-one million, six hundred six thousand, four hundred".