21494143 has 16 divisors (see below), whose sum is σ = 24141312. Its totient is φ = 18972000.

The previous prime is 21494131. The next prime is 21494159. The reversal of 21494143 is 34149412.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21494143 is a prime.

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

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21494173) 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, 68958 + ... + 69268.

It is an arithmetic number, because the mean of its divisors is an integer number (1508832).

Almost surely, 2^21494143 is an apocalyptic number.

21494143 is a deficient number, since it is larger than the sum of its proper divisors (2647169).

21494143 is a wasteful number, since it uses less digits than its factorization.

21494143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 486.

The product of its digits is 3456, while the sum is 28.

The square root of 21494143 is about 4636.1776281760. The cubic root of 21494143 is about 278.0396360166.

The spelling of 21494143 in words is "twenty-one million, four hundred ninety-four thousand, one hundred forty-three".