66637153738 has 4 divisors (see below), whose sum is σ = 99955730610. Its totient is φ = 33318576868.

The previous prime is 66637153733. The next prime is 66637153747. The reversal of 66637153738 is 83735173666.

66637153738 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83735173666 = 2 ⋅41867586833.

It can be written as a sum of positive squares in only one way, i.e., 66634710769 + 2442969 = 258137^2 + 1563^2 .

It is not an unprimeable number, because it can be changed into a prime (66637153733) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16659288433 + ... + 16659288436.

Almost surely, 2^66637153738 is an apocalyptic number.

66637153738 is a deficient number, since it is larger than the sum of its proper divisors (33318576872).

66637153738 is a wasteful number, since it uses less digits than its factorization.

66637153738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33318576871.

The product of its digits is 11430720, while the sum is 55.

The spelling of 66637153738 in words is "sixty-six billion, six hundred thirty-seven million, one hundred fifty-three thousand, seven hundred thirty-eight".