1213778720 has 192 divisors, whose sum is σ = 3621252096. Its totient is φ = 373447680.

The previous prime is 1213778693. The next prime is 1213778723. The reversal of 1213778720 is 278773121.

It is a happy number.

It is a super-2 number, since 2×1213778720² = 2946517562249676800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1213778723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1021967 + ... + 1023153.

It is an arithmetic number, because the mean of its divisors is an integer number (18860688).

Almost surely, 2^1213778720 is an apocalyptic number.

1213778720 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 1213778720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1810626048).

1213778720 is an abundant number, since it is smaller than the sum of its proper divisors (2407473376).

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

1213778720 is a wasteful number, since it uses less digits than its factorization.

1213778720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1303 (or 1295 counting only the distinct ones).

The product of its (nonzero) digits is 32928, while the sum is 38.

The square root of 1213778720 is about 34839.3272036071. The cubic root of 1213778720 is about 1066.7103436976.

The spelling of 1213778720 in words is "one billion, two hundred thirteen million, seven hundred seventy-eight thousand, seven hundred twenty".