21385522747 has 2 divisors, whose sum is σ = 21385522748. Its totient is φ = 21385522746.

The previous prime is 21385522729. The next prime is 21385522799. The reversal of 21385522747 is 74722558312.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21385522747 is a prime.

It is a super-3 number, since 3×21385522747³ (a number of 32 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21385522697 and 21385522706.

It is not a weakly prime, because it can be changed into another prime (21385522247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10692761373 + 10692761374.

It is an arithmetic number, because the mean of its divisors is an integer number (10692761374).

Almost surely, 2^21385522747 is an apocalyptic number.

21385522747 is a deficient number, since it is larger than the sum of its proper divisors (1).

21385522747 is an equidigital number, since it uses as much as digits as its factorization.

21385522747 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 940800, while the sum is 46.

The spelling of 21385522747 in words is "twenty-one billion, three hundred eighty-five million, five hundred twenty-two thousand, seven hundred forty-seven".