12218042781 has 16 divisors (see below), whose sum is σ = 20686633600. Its totient is φ = 6981738624.

The previous prime is 12218042761. The next prime is 12218042797. The reversal of 12218042781 is 18724081221.

It is a happy number.

12218042781 is a `hidden beast` number, since 1 + 221 + 8 + 0 + 427 + 8 + 1 = 666.

It is not a de Polignac number, because 12218042781 - 2¹⁷ = 12217911709 is a prime.

It is a super-2 number, since 2×12218042781² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12218042761) 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, 32322676 + ... + 32323053.

It is an arithmetic number, because the mean of its divisors is an integer number (1292914600).

Almost surely, 2^12218042781 is an apocalyptic number.

It is an amenable number.

12218042781 is a deficient number, since it is larger than the sum of its proper divisors (8468590819).

12218042781 is an equidigital number, since it uses as much as digits as its factorization.

12218042781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64645745 (or 64645739 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 36.

The spelling of 12218042781 in words is "twelve billion, two hundred eighteen million, forty-two thousand, seven hundred eighty-one".