121615728 has 80 divisors (see below), whose sum is σ = 349310976. Its totient is φ = 36207360.

The previous prime is 121615723. The next prime is 121615733. The reversal of 121615728 is 827516121.

It is an interprime number because it is at equal distance from previous prime (121615723) and next prime (121615733).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121615723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16201 + ... + 22487.

Almost surely, 2^121615728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121615728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (174655488).

121615728 is an abundant number, since it is smaller than the sum of its proper divisors (227695248).

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

121615728 is a wasteful number, since it uses less digits than its factorization.

121615728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6342 (or 6336 counting only the distinct ones).

The product of its digits is 6720, while the sum is 33.

The square root of 121615728 is about 11027.9521217677. The cubic root of 121615728 is about 495.4462906991.

The spelling of 121615728 in words is "one hundred twenty-one million, six hundred fifteen thousand, seven hundred twenty-eight".