40405213 has 4 divisors (see below), whose sum is σ = 41390748. Its totient is φ = 39419680.

The previous prime is 40405187. The next prime is 40405217. The reversal of 40405213 is 31250404.

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 13344409 + 27060804 = 3653^2 + 5202^2 .

It is a cyclic number.

It is not a de Polignac number, because 40405213 - 2¹⁷ = 40274141 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40405217) 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, 492706 + ... + 492787.

It is an arithmetic number, because the mean of its divisors is an integer number (10347687).

Almost surely, 2^40405213 is an apocalyptic number.

It is an amenable number.

40405213 is a deficient number, since it is larger than the sum of its proper divisors (985535).

40405213 is an equidigital number, since it uses as much as digits as its factorization.

40405213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 985534.

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 40405213 is about 6356.5094981444. The cubic root of 40405213 is about 343.1461523031.

Adding to 40405213 its reverse (31250404), we get a palindrome (71655617).

The spelling of 40405213 in words is "forty million, four hundred five thousand, two hundred thirteen".