22478009 has 4 divisors (see below), whose sum is σ = 22520100. Its totient is φ = 22435920.

The previous prime is 22478003. The next prime is 22478023. The reversal of 22478009 is 90087422.

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 3988009 + 18490000 = 1997^2 + 4300^2 .

It is a cyclic number.

It is not a de Polignac number, because 22478009 - 2⁴ = 22477993 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (22478003) 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, 20234 + ... + 21315.

It is an arithmetic number, because the mean of its divisors is an integer number (5630025).

Almost surely, 2^22478009 is an apocalyptic number.

It is an amenable number.

22478009 is a deficient number, since it is larger than the sum of its proper divisors (42091).

22478009 is an equidigital number, since it uses as much as digits as its factorization.

22478009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42090.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 22478009 is about 4741.0978686376. The cubic root of 22478009 is about 282.2188039131.

The spelling of 22478009 in words is "twenty-two million, four hundred seventy-eight thousand, nine".