661527646406 has 8 divisors (see below), whose sum is σ = 1082499785064. Its totient is φ = 300694384720.

The previous prime is 661527646343. The next prime is 661527646447. The reversal of 661527646406 is 604646725166.

It is a happy number.

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

It is a congruent number.

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, 15034719215 + ... + 15034719258.

It is an arithmetic number, because the mean of its divisors is an integer number (135312473133).

Almost surely, 2^661527646406 is an apocalyptic number.

661527646406 is a deficient number, since it is larger than the sum of its proper divisors (420972138658).

661527646406 is a wasteful number, since it uses less digits than its factorization.

661527646406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30069438486.

The product of its (nonzero) digits is 8709120, while the sum is 53.

The spelling of 661527646406 in words is "six hundred sixty-one billion, five hundred twenty-seven million, six hundred forty-six thousand, four hundred six".