661809295634 has 8 divisors (see below), whose sum is σ = 998452174860. Its totient is φ = 328991904016.

The previous prime is 661809295613. The next prime is 661809295649. The reversal of 661809295634 is 436592908166.

It can be written as a sum of positive squares in 2 ways, for example, as 543368008225 + 118441287409 = 737135^2 + 344153^2 .

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

It is a super-2 number, since 2×661809295634² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 956371469 + ... + 956372160.

Almost surely, 2^661809295634 is an apocalyptic number.

661809295634 is a deficient number, since it is larger than the sum of its proper divisors (336642879226).

661809295634 is a wasteful number, since it uses less digits than its factorization.

661809295634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1912743804.

The product of its (nonzero) digits is 16796160, while the sum is 59.

The spelling of 661809295634 in words is "six hundred sixty-one billion, eight hundred nine million, two hundred ninety-five thousand, six hundred thirty-four".