21013145827 has 2 divisors, whose sum is σ = 21013145828. Its totient is φ = 21013145826.

The previous prime is 21013145819. The next prime is 21013145831. The reversal of 21013145827 is 72854131012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21013145827 - 2³ = 21013145819 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21013145792 and 21013145801.

It is not a weakly prime, because it can be changed into another prime (21013149827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506572913 + 10506572914.

It is an arithmetic number, because the mean of its divisors is an integer number (10506572914).

Almost surely, 2^21013145827 is an apocalyptic number.

21013145827 is a deficient number, since it is larger than the sum of its proper divisors (1).

21013145827 is an equidigital number, since it uses as much as digits as its factorization.

21013145827 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13440, while the sum is 34.

Adding to 21013145827 its reverse (72854131012), we get a palindrome (93867276839).

The spelling of 21013145827 in words is "twenty-one billion, thirteen million, one hundred forty-five thousand, eight hundred twenty-seven".