1212787840 has 96 divisors (see below), whose sum is σ = 3187060380. Its totient is φ = 440985600.

The previous prime is 1212787819. The next prime is 1212787853. The reversal of 1212787840 is 487872121.

It can be written as a sum of positive squares in 2 ways, for example, as 1124126784 + 88661056 = 33528^2 + 9416^2 .

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 1212787793 and 1212787802.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 69610 + ... + 85270.

Almost surely, 2^1212787840 is an apocalyptic number.

1212787840 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 1212787840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1593530190).

1212787840 is an abundant number, since it is smaller than the sum of its proper divisors (1974272540).

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

1212787840 is a wasteful number, since it uses less digits than its factorization.

1212787840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15702 (or 15679 counting only the distinct ones).

The product of its (nonzero) digits is 50176, while the sum is 40.

The square root of 1212787840 is about 34825.1035892214. The cubic root of 1212787840 is about 1066.4199915699.

The spelling of 1212787840 in words is "one billion, two hundred twelve million, seven hundred eighty-seven thousand, eight hundred forty".