21996757 has 2 divisors, whose sum is σ = 21996758. Its totient is φ = 21996756.

The previous prime is 21996731. The next prime is 21996797. The reversal of 21996757 is 75769912.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16048036 + 5948721 = 4006^2 + 2439^2 .

It is a cyclic number.

It is not a de Polignac number, because 21996757 - 2⁷ = 21996629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21996707) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10998378 + 10998379.

It is an arithmetic number, because the mean of its divisors is an integer number (10998379).

Almost surely, 2^21996757 is an apocalyptic number.

It is an amenable number.

21996757 is a deficient number, since it is larger than the sum of its proper divisors (1).

21996757 is an equidigital number, since it uses as much as digits as its factorization.

21996757 is an evil number, because the sum of its binary digits is even.

The product of its digits is 238140, while the sum is 46.

The square root of 21996757 is about 4690.0700421209. The cubic root of 21996757 is about 280.1901641866.

The spelling of 21996757 in words is "twenty-one million, nine hundred ninety-six thousand, seven hundred fifty-seven".