661204425037 has 4 divisors (see below), whose sum is σ = 712066303900. Its totient is φ = 610342546176.

The previous prime is 661204424989. The next prime is 661204425041. The reversal of 661204425037 is 730524402166.

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

It can be written as a sum of positive squares in 2 ways, for example, as 438388327881 + 222816097156 = 662109^2 + 472034^2 .

It is a cyclic number.

It is not a de Polignac number, because 661204425037 - 2¹⁵ = 661204392269 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661204425047) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25430939412 + ... + 25430939437.

It is an arithmetic number, because the mean of its divisors is an integer number (178016575975).

Almost surely, 2^661204425037 is an apocalyptic number.

It is an amenable number.

661204425037 is a deficient number, since it is larger than the sum of its proper divisors (50861878863).

661204425037 is a wasteful number, since it uses less digits than its factorization.

661204425037 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50861878862.

The product of its (nonzero) digits is 241920, while the sum is 40.

The spelling of 661204425037 in words is "six hundred sixty-one billion, two hundred four million, four hundred twenty-five thousand, thirty-seven".