21143697 has 8 divisors (see below), whose sum is σ = 29163840. Its totient is φ = 13609680.

The previous prime is 21143671. The next prime is 21143719. The reversal of 21143697 is 79634112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21143697 - 2⁷ = 21143569 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21143657) 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, 121429 + ... + 121602.

It is an arithmetic number, because the mean of its divisors is an integer number (3645480).

Almost surely, 2^21143697 is an apocalyptic number.

It is an amenable number.

21143697 is a deficient number, since it is larger than the sum of its proper divisors (8020143).

21143697 is a wasteful number, since it uses less digits than its factorization.

21143697 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243063.

The product of its digits is 9072, while the sum is 33.

The square root of 21143697 is about 4598.2275933233. The cubic root of 21143697 is about 276.5202720613.

The spelling of 21143697 in words is "twenty-one million, one hundred forty-three thousand, six hundred ninety-seven".