73638683978 has 4 divisors (see below), whose sum is σ = 110458025970. Its totient is φ = 36819341988.

The previous prime is 73638683977. The next prime is 73638684019. The reversal of 73638683978 is 87938683637.

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., 45184729489 + 28453954489 = 212567^2 + 168683^2 .

It is not an unprimeable number, because it can be changed into a prime (73638683977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18409670993 + ... + 18409670996.

Almost surely, 2^73638683978 is an apocalyptic number.

73638683978 is a deficient number, since it is larger than the sum of its proper divisors (36819341992).

73638683978 is a wasteful number, since it uses less digits than its factorization.

73638683978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36819341991.

The product of its digits is 219469824, while the sum is 68.

The spelling of 73638683978 in words is "seventy-three billion, six hundred thirty-eight million, six hundred eighty-three thousand, nine hundred seventy-eight".