21768495 has 32 divisors (see below), whose sum is σ = 40627200. Its totient is φ = 9948960.

The previous prime is 21768457. The next prime is 21768497. The reversal of 21768495 is 59486712.

It is not a de Polignac number, because 21768495 - 2⁶ = 21768431 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21768497) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3030 + ... + 7260.

It is an arithmetic number, because the mean of its divisors is an integer number (1269600).

Almost surely, 2^21768495 is an apocalyptic number.

21768495 is a deficient number, since it is larger than the sum of its proper divisors (18858705).

21768495 is an equidigital number, since it uses as much as digits as its factorization.

21768495 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4260 (or 4246 counting only the distinct ones).

The product of its digits is 120960, while the sum is 42.

The square root of 21768495 is about 4665.6719773255. The cubic root of 21768495 is about 279.2176074957.

The spelling of 21768495 in words is "twenty-one million, seven hundred sixty-eight thousand, four hundred ninety-five".