501010501661 has 8 divisors (see below), whose sum is σ = 508017916224. Its totient is φ = 494006986080.

The previous prime is 501010501639. The next prime is 501010501709. The reversal of 501010501661 is 166105010105.

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 501010501661 - 2¹⁰ = 501010500637 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 501010501661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (501010501261) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 715475 + ... + 1230416.

It is an arithmetic number, because the mean of its divisors is an integer number (63502239528).

Almost surely, 2^501010501661 is an apocalyptic number.

It is an amenable number.

501010501661 is a deficient number, since it is larger than the sum of its proper divisors (7007414563).

501010501661 is a wasteful number, since it uses less digits than its factorization.

501010501661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1949491.

The product of its (nonzero) digits is 900, while the sum is 26.

Adding to 501010501661 its reverse (166105010105), we get a palindrome (667115511766).

The spelling of 501010501661 in words is "five hundred one billion, ten million, five hundred one thousand, six hundred sixty-one".