21454744 has 8 divisors (see below), whose sum is σ = 40227660. Its totient is φ = 10727368.

The previous prime is 21454729. The next prime is 21454747. The reversal of 21454744 is 44745412.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21454747) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1340914 + ... + 1340929.

Almost surely, 2^21454744 is an apocalyptic number.

It is an amenable number.

21454744 is a deficient number, since it is larger than the sum of its proper divisors (18772916).

21454744 is a wasteful number, since it uses less digits than its factorization.

21454744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2681849 (or 2681845 counting only the distinct ones).

The product of its digits is 17920, while the sum is 31.

The square root of 21454744 is about 4631.9265970004. The cubic root of 21454744 is about 277.8696488768.

It can be divided in two parts, 2145 and 4744, that added together give a square (6889 = 83²).

The spelling of 21454744 in words is "twenty-one million, four hundred fifty-four thousand, seven hundred forty-four".