21560647 has 2 divisors, whose sum is σ = 21560648. Its totient is φ = 21560646.

The previous prime is 21560599. The next prime is 21560689. The reversal of 21560647 is 74606512.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21560647 - 2¹⁵ = 21527879 is a prime.

It is a super-2 number, since 2×21560647² = 929722998117218, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21560047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10780323 + 10780324.

It is an arithmetic number, because the mean of its divisors is an integer number (10780324).

Almost surely, 2^21560647 is an apocalyptic number.

21560647 is a deficient number, since it is larger than the sum of its proper divisors (1).

21560647 is an equidigital number, since it uses as much as digits as its factorization.

21560647 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 21560647 is about 4643.3443766320. The cubic root of 21560647 is about 278.3260971581.

The spelling of 21560647 in words is "twenty-one million, five hundred sixty thousand, six hundred forty-seven".