1221000221136 has 40 divisors (see below), whose sum is σ = 3155197922464. Its totient is φ = 406877834880.

The previous prime is 1221000221107. The next prime is 1221000221141. The reversal of 1221000221136 is 6311220001221.

It is a super-2 number, since 2×1221000221136² (a number of 25 digits) contains 22 as substring.

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, 3658411 + ... + 3978186.

Almost surely, 2^{1221000221136} is an apocalyptic number.

1221000221136 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1221000221136 is an abundant number, since it is smaller than the sum of its proper divisors (1934197701328).

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

1221000221136 is a wasteful number, since it uses less digits than its factorization.

1221000221136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7639939 (or 7639933 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 21.

Adding to 1221000221136 its reverse (6311220001221), we get a palindrome (7532220222357).

The spelling of 1221000221136 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-one thousand, one hundred thirty-six".