1217990400 has 432 divisors, whose sum is σ = 4501378560. Its totient is φ = 287539200.

The previous prime is 1217990377. The next prime is 1217990407. The reversal of 1217990400 is 40997121.

It is a super-2 number, since 2×1217990400² = 2967001228984320000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1217990407) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 15417561 + ... + 15417639.

Almost surely, 2^1217990400 is an apocalyptic number.

1217990400 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 1217990400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2250689280).

1217990400 is an abundant number, since it is smaller than the sum of its proper divisors (3283388160).

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

1217990400 is a wasteful number, since it uses less digits than its factorization.

1217990400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192 (or 173 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 33.

The square root of 1217990400 is about 34899.7191965781. The cubic root of 1217990400 is about 1067.9427089861.

The spelling of 1217990400 in words is "one billion, two hundred seventeen million, nine hundred ninety thousand, four hundred".