1218021216 has 48 divisors (see below), whose sum is σ = 3228987888. Its totient is φ = 401984000.

The previous prime is 1218021209. The next prime is 1218021251. The reversal of 1218021216 is 6121208121.

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-2 number, since 2×1218021216² = 2967151365252237312, which contains 22 as substring.

It is a hoax number, since the sum of its digits (24) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53115 + ... + 72506.

It is an arithmetic number, because the mean of its divisors is an integer number (67270581).

Almost surely, 2^1218021216 is an apocalyptic number.

1218021216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1218021216 is an abundant number, since it is smaller than the sum of its proper divisors (2010966672).

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

1218021216 is a wasteful number, since it uses less digits than its factorization.

1218021216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125735 (or 125727 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 24.

The square root of 1218021216 is about 34900.1606873092. The cubic root of 1218021216 is about 1067.9517154734.

Adding to 1218021216 its reverse (6121208121), we get a palindrome (7339229337).

The spelling of 1218021216 in words is "one billion, two hundred eighteen million, twenty-one thousand, two hundred sixteen".