21677069 has 4 divisors (see below), whose sum is σ = 22205820. Its totient is φ = 21148320.

The previous prime is 21677041. The next prime is 21677077. The reversal of 21677069 is 96077612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7912969 + 13764100 = 2813^2 + 3710^2 .

It is a cyclic number.

It is not a de Polignac number, because 21677069 - 2⁸ = 21676813 is a prime.

It is a super-2 number, since 2×21677069² = 939790640861522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21677969) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 264314 + ... + 264395.

It is an arithmetic number, because the mean of its divisors is an integer number (5551455).

Almost surely, 2^21677069 is an apocalyptic number.

It is an amenable number.

21677069 is a deficient number, since it is larger than the sum of its proper divisors (528751).

21677069 is an equidigital number, since it uses as much as digits as its factorization.

21677069 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 528750.

The product of its (nonzero) digits is 31752, while the sum is 38.

The square root of 21677069 is about 4655.8639370153. The cubic root of 21677069 is about 278.8261614970.

The spelling of 21677069 in words is "twenty-one million, six hundred seventy-seven thousand, sixty-nine".