21772669 has 4 divisors (see below), whose sum is σ = 22129660. Its totient is φ = 21415680.

The previous prime is 21772607. The next prime is 21772691. The reversal of 21772669 is 96627712.

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 1863225 + 19909444 = 1365^2 + 4462^2 .

It is a cyclic number.

It is not a de Polignac number, because 21772669 - 2²¹ = 19675517 is a prime.

It is a super-2 number, since 2×21772669² = 948098230767122, 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 (21772369) 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, 178404 + ... + 178525.

It is an arithmetic number, because the mean of its divisors is an integer number (5532415).

Almost surely, 2^21772669 is an apocalyptic number.

It is an amenable number.

21772669 is a deficient number, since it is larger than the sum of its proper divisors (356991).

21772669 is an equidigital number, since it uses as much as digits as its factorization.

21772669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 356990.

The product of its digits is 63504, while the sum is 40.

The square root of 21772669 is about 4666.1192655139. The cubic root of 21772669 is about 279.2354525482.

The spelling of 21772669 in words is "twenty-one million, seven hundred seventy-two thousand, six hundred sixty-nine".