121211000172 has 36 divisors (see below), whose sum is σ = 306826687440. Its totient is φ = 40346671392.

The previous prime is 121211000171. The next prime is 121211000173. The reversal of 121211000172 is 271000112121.

It is an interprime number because it is at equal distance from previous prime (121211000171) and next prime (121211000173).

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (121211000171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2348928 + ... + 2399975.

It is an arithmetic number, because the mean of its divisors is an integer number (8522963540).

Almost surely, 2^121211000172 is an apocalyptic number.

121211000172 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

121211000172 is an abundant number, since it is smaller than the sum of its proper divisors (185615687268).

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

121211000172 is a wasteful number, since it uses less digits than its factorization.

121211000172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4749622 (or 4749617 counting only the distinct ones).

The product of its (nonzero) digits is 56, while the sum is 18.

Adding to 121211000172 its reverse (271000112121), we get a palindrome (392211112293).

The spelling of 121211000172 in words is "one hundred twenty-one billion, two hundred eleven million, one hundred seventy-two", and thus it is an aban number.