1218561948 has 48 divisors (see below), whose sum is σ = 3169289760. Its totient is φ = 404894592.

The previous prime is 1218561947. The next prime is 1218561983. The reversal of 1218561948 is 8491658121.

It is a happy number.

1218561948 is a `hidden beast` number, since 1 + 21 + 8 + 5 + 619 + 4 + 8 = 666.

It is a super-2 number, since 2×1218561948² = 2969786442227109408, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1218561947) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16440 + ... + 52032.

It is an arithmetic number, because the mean of its divisors is an integer number (66026870).

Almost surely, 2^1218561948 is an apocalyptic number.

1218561948 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1218561948 is an abundant number, since it is smaller than the sum of its proper divisors (1950727812).

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

1218561948 is a wasteful number, since it uses less digits than its factorization.

1218561948 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35923 (or 35915 counting only the distinct ones).

The product of its digits is 138240, while the sum is 45.

The square root of 1218561948 is about 34907.9066688336. The cubic root of 1218561948 is about 1068.1097286577.

The spelling of 1218561948 in words is "one billion, two hundred eighteen million, five hundred sixty-one thousand, nine hundred forty-eight".