73406021 has 4 divisors (see below), whose sum is σ = 79052652. Its totient is φ = 67759392.

The previous prime is 73406009. The next prime is 73406023. The reversal of 73406021 is 12060437.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12060437 = 41 ⋅294157.

It can be written as a sum of positive squares in 2 ways, for example, as 5013121 + 68392900 = 2239^2 + 8270^2 .

It is a cyclic number.

It is not a de Polignac number, because 73406021 - 2⁶ = 73405957 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 (73406023) 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, 2823296 + ... + 2823321.

It is an arithmetic number, because the mean of its divisors is an integer number (19763163).

Almost surely, 2^73406021 is an apocalyptic number.

It is an amenable number.

73406021 is a deficient number, since it is larger than the sum of its proper divisors (5646631).

73406021 is a wasteful number, since it uses less digits than its factorization.

73406021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5646630.

The product of its (nonzero) digits is 1008, while the sum is 23.

The square root of 73406021 is about 8567.7313800095. The cubic root of 73406021 is about 418.7073274701.

Adding to 73406021 its reverse (12060437), we get a palindrome (85466458).

The spelling of 73406021 in words is "seventy-three million, four hundred six thousand, twenty-one".