21107697 has 16 divisors (see below), whose sum is σ = 30410688. Its totient is φ = 12945600.

The previous prime is 21107641. The next prime is 21107699. The reversal of 21107697 is 79670112.

It is not a de Polignac number, because 21107697 - 2⁶ = 21107633 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21107699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13822 + ... + 15272.

It is an arithmetic number, because the mean of its divisors is an integer number (1900668).

Almost surely, 2^21107697 is an apocalyptic number.

It is an amenable number.

21107697 is a deficient number, since it is larger than the sum of its proper divisors (9302991).

21107697 is a wasteful number, since it uses less digits than its factorization.

21107697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1840.

The product of its (nonzero) digits is 5292, while the sum is 33.

The square root of 21107697 is about 4594.3113738622. The cubic root of 21107697 is about 276.3632452036.

The spelling of 21107697 in words is "twenty-one million, one hundred seven thousand, six hundred ninety-seven".