21255257741 has 2 divisors, whose sum is σ = 21255257742. Its totient is φ = 21255257740.

The previous prime is 21255257729. The next prime is 21255257869. The reversal of 21255257741 is 14775255212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12666602116 + 8588655625 = 112546^2 + 92675^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21255257741 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21255257701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10627628870 + 10627628871.

It is an arithmetic number, because the mean of its divisors is an integer number (10627628871).

Almost surely, 2^21255257741 is an apocalyptic number.

It is an amenable number.

21255257741 is a deficient number, since it is larger than the sum of its proper divisors (1).

21255257741 is an equidigital number, since it uses as much as digits as its factorization.

21255257741 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 196000, while the sum is 41.

The spelling of 21255257741 in words is "twenty-one billion, two hundred fifty-five million, two hundred fifty-seven thousand, seven hundred forty-one".