21375849 has 8 divisors (see below), whose sum is σ = 31092192. Its totient is φ = 12955040.

The previous prime is 21375847. The next prime is 21375853. The reversal of 21375849 is 94857312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21375849 - 2¹ = 21375847 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21375847) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 323844 + ... + 323909.

It is an arithmetic number, because the mean of its divisors is an integer number (3886524).

Almost surely, 2^21375849 is an apocalyptic number.

It is an amenable number.

21375849 is a deficient number, since it is larger than the sum of its proper divisors (9716343).

21375849 is a wasteful number, since it uses less digits than its factorization.

21375849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 647767.

The product of its digits is 60480, while the sum is 39.

The square root of 21375849 is about 4623.4023186394. The cubic root of 21375849 is about 277.5286294624.

The spelling of 21375849 in words is "twenty-one million, three hundred seventy-five thousand, eight hundred forty-nine".