213451409 has 4 divisors (see below), whose sum is σ = 219220404. Its totient is φ = 207682416.

The previous prime is 213451387. The next prime is 213451421. The reversal of 213451409 is 904154312.

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 112890625 + 100560784 = 10625^2 + 10028^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-213451409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213451499) 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, 2884442 + ... + 2884515.

It is an arithmetic number, because the mean of its divisors is an integer number (54805101).

Almost surely, 2^213451409 is an apocalyptic number.

It is an amenable number.

213451409 is a deficient number, since it is larger than the sum of its proper divisors (5768995).

213451409 is an equidigital number, since it uses as much as digits as its factorization.

213451409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5768994.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 213451409 is about 14609.9763517947. The cubic root of 213451409 is about 597.6308510533.

The spelling of 213451409 in words is "two hundred thirteen million, four hundred fifty-one thousand, four hundred nine".