21767229 has 12 divisors (see below), whose sum is σ = 34300032. Its totient is φ = 13192200.

The previous prime is 21767227. The next prime is 21767231. The reversal of 21767229 is 92276712.

It is an interprime number because it is at equal distance from previous prime (21767227) and next prime (21767231).

It is not a de Polignac number, because 21767229 - 2¹ = 21767227 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 21767193 and 21767202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21767227) 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 11 ways as a sum of consecutive naturals, for example, 109837 + ... + 110034.

It is an arithmetic number, because the mean of its divisors is an integer number (2858336).

Almost surely, 2^21767229 is an apocalyptic number.

It is an amenable number.

21767229 is a deficient number, since it is larger than the sum of its proper divisors (12532803).

21767229 is a wasteful number, since it uses less digits than its factorization.

21767229 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 219888 (or 219885 counting only the distinct ones).

The product of its digits is 21168, while the sum is 36.

The square root of 21767229 is about 4665.5363035775. The cubic root of 21767229 is about 279.2121945301.

The spelling of 21767229 in words is "twenty-one million, seven hundred sixty-seven thousand, two hundred twenty-nine".