1245440400 has 120 divisors (see below), whose sum is σ = 4224309984. Its totient is φ = 312576000.

The previous prime is 1245440377. The next prime is 1245440401. The reversal of 1245440400 is 40445421.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (120).

It is a super-2 number, since 2×1245440400² = 3102243579904320000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (1245440401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10126 + ... + 50925.

Almost surely, 2^1245440400 is an apocalyptic number.

1245440400 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 1245440400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2112154992).

1245440400 is an abundant number, since it is smaller than the sum of its proper divisors (2978869584).

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

1245440400 is a wasteful number, since it uses less digits than its factorization.

1245440400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61089 (or 61078 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 24.

The square root of 1245440400 is about 35290.7976673807. The cubic root of 1245440400 is about 1075.9059678380.

Adding to 1245440400 its reverse (40445421), we get a palindrome (1285885821).

The spelling of 1245440400 in words is "one billion, two hundred forty-five million, four hundred forty thousand, four hundred".