1221222201138 has 56 divisors (see below), whose sum is σ = 2746798626000. Its totient is φ = 407028851064.

The previous prime is 1221222201137. The next prime is 1221222201187. The reversal of 1221222201138 is 8311022221221.

1221222201138 is a `hidden beast` number, since 1 + 221 + 222 + 201 + 13 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (1221222201131) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 14682873 + ... + 14765811.

Almost surely, 2^{1221222201138} is an apocalyptic number.

1221222201138 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1221222201138 is an abundant number, since it is smaller than the sum of its proper divisors (1525576424862).

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

1221222201138 is an equidigital number, since it uses as much as digits as its factorization.

1221222201138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93058 (or 93043 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

Adding to 1221222201138 its reverse (8311022221221), we get a palindrome (9532244422359).

The spelling of 1221222201138 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-two million, two hundred one thousand, one hundred thirty-eight".