661626331646 has 8 divisors (see below), whose sum is σ = 1134216568560. Its totient is φ = 283554142128.

The previous prime is 661626331627. The next prime is 661626331651. The reversal of 661626331646 is 646133626166.

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

It is a junction number, because it is equal to n+sod(n) for n = 661626331594 and 661626331603.

It is a congruent number.

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, 23629511831 + ... + 23629511858.

It is an arithmetic number, because the mean of its divisors is an integer number (141777071070).

Almost surely, 2^661626331646 is an apocalyptic number.

661626331646 is a deficient number, since it is larger than the sum of its proper divisors (472590236914).

661626331646 is a wasteful number, since it uses less digits than its factorization.

661626331646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47259023698.

The product of its digits is 3359232, while the sum is 50.

The spelling of 661626331646 in words is "six hundred sixty-one billion, six hundred twenty-six million, three hundred thirty-one thousand, six hundred forty-six".