661535040511 has 8 divisors (see below), whose sum is σ = 662546476800. Its totient is φ = 660524231640.

The previous prime is 661535040499. The next prime is 661535040559. The reversal of 661535040511 is 115040535166.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661535040511 is a prime.

It is a super-2 number, since 2×661535040511² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661535041511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1975600 + ... + 2286058.

It is an arithmetic number, because the mean of its divisors is an integer number (82818309600).

Almost surely, 2^661535040511 is an apocalyptic number.

661535040511 is a deficient number, since it is larger than the sum of its proper divisors (1011436289).

661535040511 is a wasteful number, since it uses less digits than its factorization.

661535040511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313709.

The product of its (nonzero) digits is 54000, while the sum is 37.

Adding to 661535040511 its reverse (115040535166), we get a palindrome (776575575677).

The spelling of 661535040511 in words is "six hundred sixty-one billion, five hundred thirty-five million, forty thousand, five hundred eleven".