1223455667778 has 96 divisors (see below), whose sum is σ = 2825583022080. Its totient is φ = 381754343520.

The previous prime is 1223455667743. The next prime is 1223455667821. The reversal of 1223455667778 is 8777665543221.

It is a happy number.

1223455667778 is a `hidden beast` number, since 1 + 2 + 2 + 3 + 4 + 556 + 6 + 7 + 7 + 78 = 666.

It is a super-2 number, since 2×1223455667778² (a number of 25 digits) contains 22 as substring.

It is a plaindrome in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5334693 + ... + 5559303.

It is an arithmetic number, because the mean of its divisors is an integer number (29433156480).

Almost surely, 2^{1223455667778} is an apocalyptic number.

1223455667778 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1223455667778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1412791511040).

1223455667778 is an abundant number, since it is smaller than the sum of its proper divisors (1602127354302).

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

1223455667778 is a wasteful number, since it uses less digits than its factorization.

1223455667778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224924 (or 224921 counting only the distinct ones).

The product of its digits is 118540800, while the sum is 63.

The spelling of 1223455667778 in words is "one trillion, two hundred twenty-three billion, four hundred fifty-five million, six hundred sixty-seven thousand, seven hundred seventy-eight".