73440421 has 4 divisors (see below), whose sum is σ = 73880352. Its totient is φ = 73000492.

The previous prime is 73440407. The next prime is 73440439. The reversal of 73440421 is 12404437.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 73440421 - 2⁷ = 73440293 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 (73444421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 219715 + ... + 220048.

It is an arithmetic number, because the mean of its divisors is an integer number (18470088).

Almost surely, 2^73440421 is an apocalyptic number.

It is an amenable number.

73440421 is a deficient number, since it is larger than the sum of its proper divisors (439931).

73440421 is a wasteful number, since it uses less digits than its factorization.

73440421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 439930.

The product of its (nonzero) digits is 2688, while the sum is 25.

The square root of 73440421 is about 8569.7386774627. The cubic root of 73440421 is about 418.7727230262.

Adding to 73440421 its reverse (12404437), we get a palindrome (85844858).

The spelling of 73440421 in words is "seventy-three million, four hundred forty thousand, four hundred twenty-one".