1205320400 has 120 divisors (see below), whose sum is σ = 3088384920. Its totient is φ = 450478080.

The previous prime is 1205320397. The next prime is 1205320429. The reversal of 1205320400 is 40235021.

It can be written as a sum of positive squares in 12 ways, for example, as 546063424 + 659256976 = 23368^2 + 25676^2 .

It is a Harshad number since it is a multiple of its sum of digits (17).

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, 1067036 + ... + 1068164.

It is an arithmetic number, because the mean of its divisors is an integer number (25736541).

Almost surely, 2^1205320400 is an apocalyptic number.

1205320400 is a gapful number since it is divisible by the number (10) 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 1205320400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1544192460).

1205320400 is an abundant number, since it is smaller than the sum of its proper divisors (1883064520).

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

1205320400 is a wasteful number, since it uses less digits than its factorization.

1205320400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1321 (or 1310 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 1205320400 is about 34717.7245798166. The cubic root of 1205320400 is about 1064.2267451632.

Adding to 1205320400 its reverse (40235021), we get a palindrome (1245555421).

The spelling of 1205320400 in words is "one billion, two hundred five million, three hundred twenty thousand, four hundred".