21182765 has 16 divisors (see below), whose sum is σ = 27786240. Its totient is φ = 15432960.

The previous prime is 21182761. The next prime is 21182767. The reversal of 21182765 is 56728112.

It is not a de Polignac number, because 21182765 - 2² = 21182761 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21182761) 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, 1385 + ... + 6654.

It is an arithmetic number, because the mean of its divisors is an integer number (1736640).

Almost surely, 2^21182765 is an apocalyptic number.

It is an amenable number.

21182765 is a deficient number, since it is larger than the sum of its proper divisors (6603475).

21182765 is a wasteful number, since it uses less digits than its factorization.

21182765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8092.

The product of its digits is 6720, while the sum is 32.

The square root of 21182765 is about 4602.4737913431. The cubic root of 21182765 is about 276.6904795555.

The spelling of 21182765 in words is "twenty-one million, one hundred eighty-two thousand, seven hundred sixty-five".