21017297 has 16 divisors (see below), whose sum is σ = 24995712. Its totient is φ = 17297280.

The previous prime is 21017279. The next prime is 21017303. The reversal of 21017297 is 79271012.

It is not a de Polignac number, because 21017297 - 2⁶ = 21017233 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21017197) 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, 18683 + ... + 19775.

It is an arithmetic number, because the mean of its divisors is an integer number (1562232).

Almost surely, 2^21017297 is an apocalyptic number.

It is an amenable number.

21017297 is a deficient number, since it is larger than the sum of its proper divisors (3978415).

21017297 is a wasteful number, since it uses less digits than its factorization.

21017297 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1208.

The product of its (nonzero) digits is 1764, while the sum is 29.

The square root of 21017297 is about 4584.4625639218. The cubic root of 21017297 is about 275.9681446466.

The spelling of 21017297 in words is "twenty-one million, seventeen thousand, two hundred ninety-seven".