21767005 has 8 divisors (see below), whose sum is σ = 28129752. Its totient is φ = 16074048.

The previous prime is 21766981. The next prime is 21767029. The reversal of 21767005 is 50076712.

It is an interprime number because it is at equal distance from previous prime (21766981) and next prime (21767029).

It can be written as a sum of positive squares in 4 ways, for example, as 2643876 + 19123129 = 1626^2 + 4373^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21767005 - 2¹⁹ = 21242717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 167374 + ... + 167503.

It is an arithmetic number, because the mean of its divisors is an integer number (3516219).

Almost surely, 2^21767005 is an apocalyptic number.

It is an amenable number.

21767005 is a deficient number, since it is larger than the sum of its proper divisors (6362747).

21767005 is a wasteful number, since it uses less digits than its factorization.

21767005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 334895.

The product of its (nonzero) digits is 2940, while the sum is 28.

The square root of 21767005 is about 4665.5122977011. The cubic root of 21767005 is about 279.2112367639.

The spelling of 21767005 in words is "twenty-one million, seven hundred sixty-seven thousand, five".