21452745 has 8 divisors (see below), whose sum is σ = 34324416. Its totient is φ = 11441456.

The previous prime is 21452741. The next prime is 21452747. The reversal of 21452745 is 54725412.

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 21452745 - 2² = 21452741 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21452741) 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, 715077 + ... + 715106.

It is an arithmetic number, because the mean of its divisors is an integer number (4290552).

Almost surely, 2^21452745 is an apocalyptic number.

It is an amenable number.

21452745 is a deficient number, since it is larger than the sum of its proper divisors (12871671).

21452745 is a wasteful number, since it uses less digits than its factorization.

21452745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1430191.

The product of its digits is 11200, while the sum is 30.

The square root of 21452745 is about 4631.7108070345. The cubic root of 21452745 is about 277.8610186381.

The spelling of 21452745 in words is "twenty-one million, four hundred fifty-two thousand, seven hundred forty-five".