1213977856 has 216 divisors, whose sum is σ = 3155543552. Its totient is φ = 453427200.

The previous prime is 1213977847. The next prime is 1213977857. The reversal of 1213977856 is 6587793121.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213977857) 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, 29609196 + ... + 29609236.

Almost surely, 2^1213977856 is an apocalyptic number.

1213977856 is a gapful number since it is divisible by the number (16) 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 1213977856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1577771776).

1213977856 is an abundant number, since it is smaller than the sum of its proper divisors (1941565696).

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

1213977856 is an equidigital number, since it uses as much as digits as its factorization.

1213977856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149 (or 94 counting only the distinct ones).

The product of its digits is 635040, while the sum is 49.

The square root of 1213977856 is about 34842.1850061101. The cubic root of 1213977856 is about 1066.7686763552.

The spelling of 1213977856 in words is "one billion, two hundred thirteen million, nine hundred seventy-seven thousand, eight hundred fifty-six".