1216281540 has 48 divisors (see below), whose sum is σ = 3432425472. Its totient is φ = 321785856.

The previous prime is 1216281533. The next prime is 1216281581. The reversal of 1216281540 is 451826121.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 1216281498 and 1216281507.

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, 72189 + ... + 87428.

It is an arithmetic number, because the mean of its divisors is an integer number (71508864).

Almost surely, 2^1216281540 is an apocalyptic number.

1216281540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1216281540 is an abundant number, since it is smaller than the sum of its proper divisors (2216143932).

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

1216281540 is a wasteful number, since it uses less digits than its factorization.

1216281540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159756 (or 159754 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 30.

The square root of 1216281540 is about 34875.2281712966. The cubic root of 1216281540 is about 1067.4430283296.

The spelling of 1216281540 in words is "one billion, two hundred sixteen million, two hundred eighty-one thousand, five hundred forty".