661500501 has 8 divisors (see below), whose sum is σ = 882199200. Its totient is φ = 440901072.

The previous prime is 661500491. The next prime is 661500517. The reversal of 661500501 is 105005166.

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

It is not a de Polignac number, because 661500501 - 2⁹ = 661499989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661500551) 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 7 ways as a sum of consecutive naturals, for example, 7551 + ... + 37148.

It is an arithmetic number, because the mean of its divisors is an integer number (110274900).

Almost surely, 2^661500501 is an apocalyptic number.

It is an amenable number.

661500501 is a deficient number, since it is larger than the sum of its proper divisors (220698699).

661500501 is a wasteful number, since it uses less digits than its factorization.

661500501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49635.

The product of its (nonzero) digits is 900, while the sum is 24.

The square root of 661500501 is about 25719.6520388593. The cubic root of 661500501 is about 871.3180800044.

Adding to 661500501 its reverse (105005166), we get a palindrome (766505667).

The spelling of 661500501 in words is "six hundred sixty-one million, five hundred thousand, five hundred one".