21453783 has 16 divisors (see below), whose sum is σ = 31559136. Its totient is φ = 12879360.

The previous prime is 21453769. The next prime is 21453787. The reversal of 21453783 is 38735412.

It is not a de Polignac number, because 21453783 - 2²⁰ = 20405207 is a prime.

It is a super-2 number, since 2×21453783² = 920529610022178, which contains 22 as substring.

It is a plaindrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21453787) 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, 5110 + ... + 8307.

It is an arithmetic number, because the mean of its divisors is an integer number (1972446).

Almost surely, 2^21453783 is an apocalyptic number.

21453783 is a deficient number, since it is larger than the sum of its proper divisors (10105353).

21453783 is a wasteful number, since it uses less digits than its factorization.

21453783 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13474.

The product of its digits is 20160, while the sum is 33.

The square root of 21453783 is about 4631.8228593071. The cubic root of 21453783 is about 277.8655000396.

The spelling of 21453783 in words is "twenty-one million, four hundred fifty-three thousand, seven hundred eighty-three".