121721015 has 8 divisors (see below), whose sum is σ = 157301088. Its totient is φ = 89886240.

The previous prime is 121720999. The next prime is 121721021. The reversal of 121721015 is 510127121.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 121721015 - 2⁴ = 121720999 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 936251 + ... + 936380.

It is an arithmetic number, because the mean of its divisors is an integer number (19662636).

Almost surely, 2^121721015 is an apocalyptic number.

121721015 is a deficient number, since it is larger than the sum of its proper divisors (35580073).

121721015 is a wasteful number, since it uses less digits than its factorization.

121721015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1872649.

The product of its (nonzero) digits is 140, while the sum is 20.

The square root of 121721015 is about 11032.7247314523. The cubic root of 121721015 is about 495.5892245348.

Adding to 121721015 its reverse (510127121), we get a palindrome (631848136).

The spelling of 121721015 in words is "one hundred twenty-one million, seven hundred twenty-one thousand, fifteen".