1216062640 has 80 divisors (see below), whose sum is σ = 3051367200. Its totient is φ = 448045056.

The previous prime is 1216062619. The next prime is 1216062671. The reversal of 1216062640 is 462606121.

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 1216062599 and 1216062608.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 642816 + ... + 644704.

It is an arithmetic number, because the mean of its divisors is an integer number (38142090).

Almost surely, 2^1216062640 is an apocalyptic number.

1216062640 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 1216062640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1525683600).

1216062640 is an abundant number, since it is smaller than the sum of its proper divisors (1835304560).

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

1216062640 is a wasteful number, since it uses less digits than its factorization.

1216062640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2534 (or 2528 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 1216062640 is about 34872.0896993570. The cubic root of 1216062640 is about 1067.3789868801.

Adding to 1216062640 its reverse (462606121), we get a palindrome (1678668761).

The spelling of 1216062640 in words is "one billion, two hundred sixteen million, sixty-two thousand, six hundred forty".