121215612 has 72 divisors (see below), whose sum is σ = 343357056. Its totient is φ = 33123552.

The previous prime is 121215599. The next prime is 121215617. The reversal of 121215612 is 216512121.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121215617) 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, 9043 + ... + 18005.

It is an arithmetic number, because the mean of its divisors is an integer number (4768848).

Almost surely, 2^121215612 is an apocalyptic number.

121215612 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121215612, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (171678528).

121215612 is an abundant number, since it is smaller than the sum of its proper divisors (222141444).

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

121215612 is a wasteful number, since it uses less digits than its factorization.

121215612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9007 (or 8998 counting only the distinct ones).

The product of its digits is 240, while the sum is 21.

The square root of 121215612 is about 11009.7961833996. The cubic root of 121215612 is about 494.9023539664.

Adding to 121215612 its reverse (216512121), we get a palindrome (337727733).

The spelling of 121215612 in words is "one hundred twenty-one million, two hundred fifteen thousand, six hundred twelve".