21450923 has 16 divisors (see below), whose sum is σ = 25310880. Its totient is φ = 17988096.

The previous prime is 21450917. The next prime is 21450929. The reversal of 21450923 is 32905412.

It is an interprime number because it is at equal distance from previous prime (21450917) and next prime (21450929).

It is a cyclic number.

It is not a de Polignac number, because 21450923 - 2⁴ = 21450907 is a prime.

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

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21450892 and 21450901.

It is not an unprimeable number, because it can be changed into a prime (21450929) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4736 + ... + 8082.

It is an arithmetic number, because the mean of its divisors is an integer number (1581930).

Almost surely, 2^21450923 is an apocalyptic number.

21450923 is a deficient number, since it is larger than the sum of its proper divisors (3859957).

21450923 is a wasteful number, since it uses less digits than its factorization.

21450923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3406.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 21450923 is about 4631.5141152759. The cubic root of 21450923 is about 277.8531520907.

The spelling of 21450923 in words is "twenty-one million, four hundred fifty thousand, nine hundred twenty-three".