215257493 has 4 divisors (see below), whose sum is σ = 234826368. Its totient is φ = 195688620.

The previous prime is 215257487. The next prime is 215257543. The reversal of 215257493 is 394752512.

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 215257493 - 2¹² = 215253397 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 (215257463) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9784421 + ... + 9784442.

It is an arithmetic number, because the mean of its divisors is an integer number (58706592).

Almost surely, 2^215257493 is an apocalyptic number.

It is an amenable number.

215257493 is a deficient number, since it is larger than the sum of its proper divisors (19568875).

215257493 is a wasteful number, since it uses less digits than its factorization.

215257493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19568874.

The product of its digits is 75600, while the sum is 38.

The square root of 215257493 is about 14671.6561096558. The cubic root of 215257493 is about 599.3117042353.

The spelling of 215257493 in words is "two hundred fifteen million, two hundred fifty-seven thousand, four hundred ninety-three".