61638833873 has 4 divisors (see below), whose sum is σ = 63304748340. Its totient is φ = 59972919408.

The previous prime is 61638833821. The next prime is 61638833881. The reversal of 61638833873 is 37833883616.

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 59625337489 + 2013496384 = 244183^2 + 44872^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61638833873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61638833813) 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, 832957178 + ... + 832957251.

It is an arithmetic number, because the mean of its divisors is an integer number (15826187085).

Almost surely, 2^61638833873 is an apocalyptic number.

It is an amenable number.

61638833873 is a deficient number, since it is larger than the sum of its proper divisors (1665914467).

61638833873 is a wasteful number, since it uses less digits than its factorization.

61638833873 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1665914466.

The product of its digits is 10450944, while the sum is 56.

The spelling of 61638833873 in words is "sixty-one billion, six hundred thirty-eight million, eight hundred thirty-three thousand, eight hundred seventy-three".