661630062538 has 4 divisors (see below), whose sum is σ = 992445093810. Its totient is φ = 330815031268.

The previous prime is 661630062529. The next prime is 661630062553. The reversal of 661630062538 is 835260036166.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 659218957929 + 2411104609 = 811923^2 + 49103^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165407515633 + ... + 165407515636.

Almost surely, 2^661630062538 is an apocalyptic number.

661630062538 is a deficient number, since it is larger than the sum of its proper divisors (330815031272).

661630062538 is a wasteful number, since it uses less digits than its factorization.

661630062538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330815031271.

The product of its (nonzero) digits is 933120, while the sum is 46.

The spelling of 661630062538 in words is "six hundred sixty-one billion, six hundred thirty million, sixty-two thousand, five hundred thirty-eight".