1217171978400 has 288 divisors, whose sum is σ = 4724745596928. Its totient is φ = 266114534400.

The previous prime is 1217171978383. The next prime is 1217171978419. The reversal of 1217171978400 is 48791717121.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 1217171978400.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1188616 + ... + 1961415.

It is an arithmetic number, because the mean of its divisors is an integer number (16405366656).

Almost surely, 2^{1217171978400} is an apocalyptic number.

1217171978400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1217171978400 is an abundant number, since it is smaller than the sum of its proper divisors (3507573618528).

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

1217171978400 is a wasteful number, since it uses less digits than its factorization.

1217171978400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3150084 (or 3150071 counting only the distinct ones).

The product of its (nonzero) digits is 197568, while the sum is 48.

The spelling of 1217171978400 in words is "one trillion, two hundred seventeen billion, one hundred seventy-one million, nine hundred seventy-eight thousand, four hundred".