73400221 has 4 divisors (see below), whose sum is σ = 73417500. Its totient is φ = 73382944.

The previous prime is 73400213. The next prime is 73400233. The reversal of 73400221 is 12200437.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 16924996 + 56475225 = 4114^2 + 7515^2 .

It is a cyclic number.

It is not a de Polignac number, because 73400221 - 2³ = 73400213 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 (73400251) 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, 2655 + ... + 12403.

It is an arithmetic number, because the mean of its divisors is an integer number (18354375).

Almost surely, 2^73400221 is an apocalyptic number.

It is an amenable number.

73400221 is a deficient number, since it is larger than the sum of its proper divisors (17279).

73400221 is an equidigital number, since it uses as much as digits as its factorization.

73400221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17278.

The product of its (nonzero) digits is 336, while the sum is 19.

The square root of 73400221 is about 8567.3928939906. The cubic root of 73400221 is about 418.6962994626.

Adding to 73400221 its reverse (12200437), we get a palindrome (85600658).

The spelling of 73400221 in words is "seventy-three million, four hundred thousand, two hundred twenty-one".