121557715 has 8 divisors (see below), whose sum is σ = 145984608. Its totient is φ = 97169280.

The previous prime is 121557697. The next prime is 121557773. The reversal of 121557715 is 517755121.

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

It is not a de Polignac number, because 121557715 - 2¹⁵ = 121524947 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 2127 + ... + 15736.

It is an arithmetic number, because the mean of its divisors is an integer number (18248076).

Almost surely, 2^121557715 is an apocalyptic number.

121557715 is a deficient number, since it is larger than the sum of its proper divisors (24426893).

121557715 is a wasteful number, since it uses less digits than its factorization.

121557715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19229.

The product of its digits is 12250, while the sum is 34.

The square root of 121557715 is about 11025.3215372614. The cubic root of 121557715 is about 495.3674990890.

The spelling of 121557715 in words is "one hundred twenty-one million, five hundred fifty-seven thousand, seven hundred fifteen".