21877733 has 2 divisors, whose sum is σ = 21877734. Its totient is φ = 21877732.

The previous prime is 21877729. The next prime is 21877771. The reversal of 21877733 is 33777812.

It is an a-pointer prime, because the next prime (21877771) can be obtained adding 21877733 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21836929 + 40804 = 4673^2 + 202^2 .

It is a cyclic number.

It is not a de Polignac number, because 21877733 - 2² = 21877729 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21877783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10938866 + 10938867.

It is an arithmetic number, because the mean of its divisors is an integer number (10938867).

Almost surely, 2^21877733 is an apocalyptic number.

It is an amenable number.

21877733 is a deficient number, since it is larger than the sum of its proper divisors (1).

21877733 is an equidigital number, since it uses as much as digits as its factorization.

21877733 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 49392, while the sum is 38.

The square root of 21877733 is about 4677.3638943319. The cubic root of 21877733 is about 279.6838821853.

The spelling of 21877733 in words is "twenty-one million, eight hundred seventy-seven thousand, seven hundred thirty-three".