21357711049 has 2 divisors, whose sum is σ = 21357711050. Its totient is φ = 21357711048.

The previous prime is 21357711043. The next prime is 21357711119. The reversal of 21357711049 is 94011775312.

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., 13726465600 + 7631245449 = 117160^2 + 87357^2 .

It is a cyclic number.

It is not a de Polignac number, because 21357711049 - 2⁵ = 21357711017 is a prime.

It is not a weakly prime, because it can be changed into another prime (21357711043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10678855524 + 10678855525.

It is an arithmetic number, because the mean of its divisors is an integer number (10678855525).

Almost surely, 2^21357711049 is an apocalyptic number.

It is an amenable number.

21357711049 is a deficient number, since it is larger than the sum of its proper divisors (1).

21357711049 is an equidigital number, since it uses as much as digits as its factorization.

21357711049 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 52920, while the sum is 40.

The spelling of 21357711049 in words is "twenty-one billion, three hundred fifty-seven million, seven hundred eleven thousand, forty-nine".