661763544047506 has 8 divisors (see below), whose sum is σ = 992692154492604. Its totient is φ = 330866159216640.

The previous prime is 661763544047479. The next prime is 661763544047569. The reversal of 661763544047506 is 605740445367166.

It can be written as a sum of positive squares in 2 ways, for example, as 659313721181025 + 2449822866481 = 25677105^2 + 1565191^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7806350575 + ... + 7806435346.

Almost surely, 2^{661763544047506} is an apocalyptic number.

661763544047506 is a deficient number, since it is larger than the sum of its proper divisors (330928610445098).

661763544047506 is a wasteful number, since it uses less digits than its factorization.

661763544047506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15612807116.

The product of its (nonzero) digits is 304819200, while the sum is 64.

The spelling of 661763544047506 in words is "six hundred sixty-one trillion, seven hundred sixty-three billion, five hundred forty-four million, forty-seven thousand, five hundred six".