1216998720 has 672 divisors, whose sum is σ = 5237975808. Its totient is φ = 253034496.

The previous prime is 1216998707. The next prime is 1216998721. The reversal of 1216998720 is 278996121.

It is a tau number, because it is divible by the number of its divisors (672).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216998721) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 18164127 + ... + 18164193.

Almost surely, 2^1216998720 is an apocalyptic number.

1216998720 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 1216998720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2618987904).

1216998720 is an abundant number, since it is smaller than the sum of its proper divisors (4020977088).

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

1216998720 is a wasteful number, since it uses less digits than its factorization.

1216998720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167 (or 154 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 45.

The square root of 1216998720 is about 34885.5087393032. The cubic root of 1216998720 is about 1067.6527929130.

It can be divided in two parts, 12169 and 98720, that added together give a square (110889 = 333²).

The spelling of 1216998720 in words is "one billion, two hundred sixteen million, nine hundred ninety-eight thousand, seven hundred twenty".