1242120400 has 120 divisors (see below), whose sum is σ = 3112102400. Its totient is φ = 475891200.

The previous prime is 1242120367. The next prime is 1242120427. The reversal of 1242120400 is 40212421.

It is a Harshad number since it is a multiple of its sum of digits (16).

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, 1351141 + ... + 1352059.

Almost surely, 2^1242120400 is an apocalyptic number.

1242120400 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 1242120400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1556051200).

1242120400 is an abundant number, since it is smaller than the sum of its proper divisors (1869982000).

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

1242120400 is a wasteful number, since it uses less digits than its factorization.

1242120400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1077 (or 1066 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 1242120400 is about 35243.7285201211. The cubic root of 1242120400 is about 1074.9490943985.

Adding to 1242120400 its reverse (40212421), we get a palindrome (1282332821).

The spelling of 1242120400 in words is "one billion, two hundred forty-two million, one hundred twenty thousand, four hundred".