65778973637 has 4 divisors (see below), whose sum is σ = 70838894700. Its totient is φ = 60719052576.

The previous prime is 65778973633. The next prime is 65778973649. The reversal of 65778973637 is 73637987756.

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 17487153121 + 48291820516 = 132239^2 + 219754^2 .

It is not a de Polignac number, because 65778973637 - 2² = 65778973633 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 (65778973633) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2529960512 + ... + 2529960537.

It is an arithmetic number, because the mean of its divisors is an integer number (17709723675).

Almost surely, 2^65778973637 is an apocalyptic number.

It is an amenable number.

65778973637 is a deficient number, since it is larger than the sum of its proper divisors (5059921063).

65778973637 is a wasteful number, since it uses less digits than its factorization.

65778973637 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5059921062.

The product of its digits is 280052640, while the sum is 68.

The spelling of 65778973637 in words is "sixty-five billion, seven hundred seventy-eight million, nine hundred seventy-three thousand, six hundred thirty-seven".