73991640077 has 4 divisors (see below), whose sum is σ = 73992670716. Its totient is φ = 73990609440.

The previous prime is 73991640049. The next prime is 73991640097. The reversal of 73991640077 is 77004619937.

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 27858614281 + 46133025796 = 166909^2 + 214786^2 .

It is a cyclic number.

It is not a de Polignac number, because 73991640077 - 2²² = 73987445773 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 (73991640097) 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, 398858 + ... + 554139.

It is an arithmetic number, because the mean of its divisors is an integer number (18498167679).

Almost surely, 2^73991640077 is an apocalyptic number.

It is an amenable number.

73991640077 is a deficient number, since it is larger than the sum of its proper divisors (1030639).

73991640077 is an equidigital number, since it uses as much as digits as its factorization.

73991640077 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1030638.

The product of its (nonzero) digits is 2000376, while the sum is 53.

The spelling of 73991640077 in words is "seventy-three billion, nine hundred ninety-one million, six hundred forty thousand, seventy-seven".