21916877 has 2 divisors, whose sum is σ = 21916878. Its totient is φ = 21916876.

The previous prime is 21916871. The next prime is 21916889. The reversal of 21916877 is 77861912.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21031396 + 885481 = 4586^2 + 941^2 .

It is a cyclic number.

It is not a de Polignac number, because 21916877 - 2¹⁴ = 21900493 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21916871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10958438 + 10958439.

It is an arithmetic number, because the mean of its divisors is an integer number (10958439).

Almost surely, 2^21916877 is an apocalyptic number.

It is an amenable number.

21916877 is a deficient number, since it is larger than the sum of its proper divisors (1).

21916877 is an equidigital number, since it uses as much as digits as its factorization.

21916877 is an evil number, because the sum of its binary digits is even.

The product of its digits is 42336, while the sum is 41.

The square root of 21916877 is about 4681.5464325370. The cubic root of 21916877 is about 279.8505878026.

The spelling of 21916877 in words is "twenty-one million, nine hundred sixteen thousand, eight hundred seventy-seven".