1221000212133 has 24 divisors (see below), whose sum is σ = 1969679359648. Its totient is φ = 751384743984.

The previous prime is 1221000212129. The next prime is 1221000212137. The reversal of 1221000212133 is 3312120001221.

It is an interprime number because it is at equal distance from previous prime (1221000212129) and next prime (1221000212137).

It is not a de Polignac number, because 1221000212133 - 2² = 1221000212129 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221000212137) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 193254235 + ... + 193260552.

Almost surely, 2^{1221000212133} is an apocalyptic number.

1221000212133 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1221000212133 is a deficient number, since it is larger than the sum of its proper divisors (748679147515).

1221000212133 is an equidigital number, since it uses as much as digits as its factorization.

1221000212133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 386514815 (or 386514803 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 1221000212133 its reverse (3312120001221), we get a palindrome (4533120213354).

The spelling of 1221000212133 in words is "one trillion, two hundred twenty-one billion, two hundred twelve thousand, one hundred thirty-three".