21768097 has 16 divisors (see below), whose sum is σ = 24998400. Its totient is φ = 18798912.

The previous prime is 21768059. The next prime is 21768101. The reversal of 21768097 is 79086712.

It is not a de Polignac number, because 21768097 - 2¹¹ = 21766049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21768037) 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, 13279 + ... + 14827.

It is an arithmetic number, because the mean of its divisors is an integer number (1562400).

Almost surely, 2^21768097 is an apocalyptic number.

It is an amenable number.

21768097 is a deficient number, since it is larger than the sum of its proper divisors (3230303).

21768097 is a wasteful number, since it uses less digits than its factorization.

21768097 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1632.

The product of its (nonzero) digits is 42336, while the sum is 40.

The square root of 21768097 is about 4665.6293251822. The cubic root of 21768097 is about 279.2159058119.

The spelling of 21768097 in words is "twenty-one million, seven hundred sixty-eight thousand, ninety-seven".