21730797 has 12 divisors (see below), whose sum is σ = 34242624. Its totient is φ = 13170120.

The previous prime is 21730769. The next prime is 21730799. The reversal of 21730797 is 79703712.

It is not a de Polignac number, because 21730797 - 2¹² = 21726701 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21730799) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 109653 + ... + 109850.

It is an arithmetic number, because the mean of its divisors is an integer number (2853552).

Almost surely, 2^21730797 is an apocalyptic number.

It is an amenable number.

21730797 is a deficient number, since it is larger than the sum of its proper divisors (12511827).

21730797 is a wasteful number, since it uses less digits than its factorization.

21730797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 219520 (or 219517 counting only the distinct ones).

The product of its (nonzero) digits is 18522, while the sum is 36.

The square root of 21730797 is about 4661.6302942211. The cubic root of 21730797 is about 279.0563342521.

The spelling of 21730797 in words is "twenty-one million, seven hundred thirty thousand, seven hundred ninety-seven".