21545759 has 2 divisors, whose sum is σ = 21545760. Its totient is φ = 21545758.

The previous prime is 21545723. The next prime is 21545773. The reversal of 21545759 is 95754512.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21545759 - 2¹⁶ = 21480223 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 (21545789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10772879 + 10772880.

It is an arithmetic number, because the mean of its divisors is an integer number (10772880).

Almost surely, 2^21545759 is an apocalyptic number.

21545759 is a deficient number, since it is larger than the sum of its proper divisors (1).

21545759 is an equidigital number, since it uses as much as digits as its factorization.

21545759 is an evil number, because the sum of its binary digits is even.

The product of its digits is 63000, while the sum is 38.

The square root of 21545759 is about 4641.7409449473. The cubic root of 21545759 is about 278.2620194108.

The spelling of 21545759 in words is "twenty-one million, five hundred forty-five thousand, seven hundred fifty-nine".