215453989 has 4 divisors (see below), whose sum is σ = 215497260. Its totient is φ = 215410720.

The previous prime is 215453983. The next prime is 215454007. The reversal of 215453989 is 989354512.

215453989 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 45360225 + 170093764 = 6735^2 + 13042^2 .

It is a cyclic number.

It is not a de Polignac number, because 215453989 - 2³ = 215453981 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 (215453981) 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, 13024 + ... + 24505.

It is an arithmetic number, because the mean of its divisors is an integer number (53874315).

Almost surely, 2^215453989 is an apocalyptic number.

It is an amenable number.

215453989 is a deficient number, since it is larger than the sum of its proper divisors (43271).

215453989 is an equidigital number, since it uses as much as digits as its factorization.

215453989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43270.

The product of its digits is 388800, while the sum is 46.

The square root of 215453989 is about 14678.3510313659. The cubic root of 215453989 is about 599.4940076655.

The spelling of 215453989 in words is "two hundred fifteen million, four hundred fifty-three thousand, nine hundred eighty-nine".