661831015 has 8 divisors (see below), whose sum is σ = 796704480. Its totient is φ = 527793312.

The previous prime is 661831013. The next prime is 661831021. The reversal of 661831015 is 510138166.

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

It is a cyclic number.

It is not a de Polignac number, because 661831015 - 2¹ = 661831013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661831013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 207195 + ... + 210364.

It is an arithmetic number, because the mean of its divisors is an integer number (99588060).

Almost surely, 2^661831015 is an apocalyptic number.

661831015 is a deficient number, since it is larger than the sum of its proper divisors (134873465).

661831015 is a wasteful number, since it uses less digits than its factorization.

661831015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 417881.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 661831015 is about 25726.0765566769. The cubic root of 661831015 is about 871.4631717939.

The spelling of 661831015 in words is "six hundred sixty-one million, eight hundred thirty-one thousand, fifteen".