73440090721 has 4 divisors (see below), whose sum is σ = 73442999700. Its totient is φ = 73437181744.

The previous prime is 73440090701. The next prime is 73440090733. The reversal of 73440090721 is 12709004437.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12709004437 = 70313 ⋅180749.

It can be written as a sum of positive squares in 2 ways, for example, as 47857687696 + 25582403025 = 218764^2 + 159945^2 .

It is a cyclic number.

It is not a de Polignac number, because 73440090721 - 2¹⁹ = 73439566433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (73440090701) 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, 1416286 + ... + 1467223.

It is an arithmetic number, because the mean of its divisors is an integer number (18360749925).

Almost surely, 2^73440090721 is an apocalyptic number.

It is an amenable number.

73440090721 is a deficient number, since it is larger than the sum of its proper divisors (2908979).

73440090721 is a wasteful number, since it uses less digits than its factorization.

73440090721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2908978.

The product of its (nonzero) digits is 42336, while the sum is 37.

The spelling of 73440090721 in words is "seventy-three billion, four hundred forty million, ninety thousand, seven hundred twenty-one".