21570379 has 2 divisors, whose sum is σ = 21570380. Its totient is φ = 21570378.

The previous prime is 21570317. The next prime is 21570383. The reversal of 21570379 is 97307512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21570379 - 2¹¹ = 21568331 is a prime.

It is not a weakly prime, because it can be changed into another prime (21670379) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10785189 + 10785190.

It is an arithmetic number, because the mean of its divisors is an integer number (10785190).

Almost surely, 2^21570379 is an apocalyptic number.

21570379 is a deficient number, since it is larger than the sum of its proper divisors (1).

21570379 is an equidigital number, since it uses as much as digits as its factorization.

21570379 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13230, while the sum is 34.

The square root of 21570379 is about 4644.3922099668. The cubic root of 21570379 is about 278.3679676106.

The spelling of 21570379 in words is "twenty-one million, five hundred seventy thousand, three hundred seventy-nine".