21294005 has 4 divisors (see below), whose sum is σ = 25552812. Its totient is φ = 17035200.

The previous prime is 21294001. The next prime is 21294029. The reversal of 21294005 is 50049212.

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 3129361 + 18164644 = 1769^2 + 4262^2 .

It is not a de Polignac number, because 21294005 - 2² = 21294001 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21294001) 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, 2129396 + ... + 2129405.

It is an arithmetic number, because the mean of its divisors is an integer number (6388203).

Almost surely, 2^21294005 is an apocalyptic number.

It is an amenable number.

21294005 is a deficient number, since it is larger than the sum of its proper divisors (4258807).

21294005 is an equidigital number, since it uses as much as digits as its factorization.

21294005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4258806.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 21294005 is about 4614.5427725832. The cubic root of 21294005 is about 277.1739752572.

The spelling of 21294005 in words is "twenty-one million, two hundred ninety-four thousand, five".