21141779 has 2 divisors, whose sum is σ = 21141780. Its totient is φ = 21141778.

The previous prime is 21141751. The next prime is 21141787. The reversal of 21141779 is 97714112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21141779 is a prime.

It is a Chen prime.

It is equal to p_1338368 and since 21141779 and 1338368 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (21146779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10570889 + 10570890.

It is an arithmetic number, because the mean of its divisors is an integer number (10570890).

Almost surely, 2^21141779 is an apocalyptic number.

21141779 is a deficient number, since it is larger than the sum of its proper divisors (1).

21141779 is an equidigital number, since it uses as much as digits as its factorization.

21141779 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3528, while the sum is 32.

The square root of 21141779 is about 4598.0190299737. The cubic root of 21141779 is about 276.5119105164.

The spelling of 21141779 in words is "twenty-one million, one hundred forty-one thousand, seven hundred seventy-nine".