21045767 has 2 divisors, whose sum is σ = 21045768. Its totient is φ = 21045766.

The previous prime is 21045763. The next prime is 21045769. The reversal of 21045767 is 76754012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21045767 - 2² = 21045763 is a prime.

Together with 21045769, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21045763) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10522883 + 10522884.

It is an arithmetic number, because the mean of its divisors is an integer number (10522884).

Almost surely, 2^21045767 is an apocalyptic number.

21045767 is a deficient number, since it is larger than the sum of its proper divisors (1).

21045767 is an equidigital number, since it uses as much as digits as its factorization.

21045767 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11760, while the sum is 32.

The square root of 21045767 is about 4587.5665662745. The cubic root of 21045767 is about 276.0926971067.

Adding to 21045767 its reverse (76754012), we get a palindrome (97799779).

It can be divided in two parts, 21045 and 767, that added together give a palindrome (21812).

The spelling of 21045767 in words is "twenty-one million, forty-five thousand, seven hundred sixty-seven".