215665253 has 4 divisors (see below), whose sum is σ = 220680768. Its totient is φ = 210649740.

The previous prime is 215665231. The next prime is 215665259. The reversal of 215665253 is 352566512.

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 215665253 - 2⁶ = 215665189 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 (215665259) 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, 2507693 + ... + 2507778.

It is an arithmetic number, because the mean of its divisors is an integer number (55170192).

Almost surely, 2^215665253 is an apocalyptic number.

It is an amenable number.

215665253 is a deficient number, since it is larger than the sum of its proper divisors (5015515).

215665253 is an equidigital number, since it uses as much as digits as its factorization.

215665253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5015514.

The product of its digits is 54000, while the sum is 35.

The square root of 215665253 is about 14685.5457167924. The cubic root of 215665253 is about 599.6898888201.

The spelling of 215665253 in words is "two hundred fifteen million, six hundred sixty-five thousand, two hundred fifty-three".