1217984140 has 24 divisors (see below), whose sum is σ = 2565027360. Its totient is φ = 485810688.

The previous prime is 1217984123. The next prime is 1217984143. The reversal of 1217984140 is 414897121.

It is a self number, because there is not a number n which added to its sum of digits gives 1217984140.

It is not an unprimeable number, because it can be changed into a prime (1217984143) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 79200 + ... + 93319.

It is an arithmetic number, because the mean of its divisors is an integer number (106876140).

Almost surely, 2^1217984140 is an apocalyptic number.

1217984140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1217984140 is an abundant number, since it is smaller than the sum of its proper divisors (1347043220).

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

1217984140 is a wasteful number, since it uses less digits than its factorization.

1217984140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172881 (or 172879 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 37.

The square root of 1217984140 is about 34899.6295109275. The cubic root of 1217984140 is about 1067.9408793787.

The spelling of 1217984140 in words is "one billion, two hundred seventeen million, nine hundred eighty-four thousand, one hundred forty".