661506115 has 16 divisors (see below), whose sum is σ = 802413216. Its totient is φ = 523494400.

The previous prime is 661506113. The next prime is 661506119. The reversal of 661506115 is 511605166.

661506115 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 661506115 - 2¹ = 661506113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661506113) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 229785 + ... + 232645.

It is an arithmetic number, because the mean of its divisors is an integer number (50150826).

Almost surely, 2^661506115 is an apocalyptic number.

661506115 is a deficient number, since it is larger than the sum of its proper divisors (140907101).

661506115 is a wasteful number, since it uses less digits than its factorization.

661506115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3350.

The product of its (nonzero) digits is 5400, while the sum is 31.

The square root of 661506115 is about 25719.7611769627. The cubic root of 661506115 is about 871.3205448883.

The spelling of 661506115 in words is "six hundred sixty-one million, five hundred six thousand, one hundred fifteen".