21807733 has 2 divisors, whose sum is σ = 21807734. Its totient is φ = 21807732.

The previous prime is 21807727. The next prime is 21807743. The reversal of 21807733 is 33770812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14311089 + 7496644 = 3783^2 + 2738^2 .

It is a cyclic number.

It is not a de Polignac number, because 21807733 - 2¹⁷ = 21676661 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21807695 and 21807704.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21807743) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10903866 + 10903867.

It is an arithmetic number, because the mean of its divisors is an integer number (10903867).

Almost surely, 2^21807733 is an apocalyptic number.

It is an amenable number.

21807733 is a deficient number, since it is larger than the sum of its proper divisors (1).

21807733 is an equidigital number, since it uses as much as digits as its factorization.

21807733 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7056, while the sum is 31.

The square root of 21807733 is about 4669.8750518617. The cubic root of 21807733 is about 279.3852712735.

The spelling of 21807733 in words is "twenty-one million, eight hundred seven thousand, seven hundred thirty-three".