1215344400 has 120 divisors (see below), whose sum is σ = 3903812640. Its totient is φ = 323205120.

The previous prime is 1215344393. The next prime is 1215344401. The reversal of 1215344400 is 44435121.

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

It is a super-2 number, since 2×1215344400² = 2954124021222720000, 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 (1215344401) 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, 518431 + ... + 520769.

It is an arithmetic number, because the mean of its divisors is an integer number (32531772).

Almost surely, 2^1215344400 is an apocalyptic number.

1215344400 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 1215344400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1951906320).

1215344400 is an abundant number, since it is smaller than the sum of its proper divisors (2688468240).

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

1215344400 is a wasteful number, since it uses less digits than its factorization.

1215344400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2793 (or 2782 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 24.

The square root of 1215344400 is about 34861.7899712565. The cubic root of 1215344400 is about 1067.1688043781.

Adding to 1215344400 its reverse (44435121), we get a palindrome (1259779521).

The spelling of 1215344400 in words is "one billion, two hundred fifteen million, three hundred forty-four thousand, four hundred".