21574778629 has 2 divisors, whose sum is σ = 21574778630. Its totient is φ = 21574778628.

The previous prime is 21574778611. The next prime is 21574778651. The reversal of 21574778629 is 92687747512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19102004100 + 2472774529 = 138210^2 + 49727^2 .

It is a cyclic number.

It is not a de Polignac number, because 21574778629 - 2⁷ = 21574778501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21574778429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10787389314 + 10787389315.

It is an arithmetic number, because the mean of its divisors is an integer number (10787389315).

Almost surely, 2^21574778629 is an apocalyptic number.

It is an amenable number.

21574778629 is a deficient number, since it is larger than the sum of its proper divisors (1).

21574778629 is an equidigital number, since it uses as much as digits as its factorization.

21574778629 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11854080, while the sum is 58.

The spelling of 21574778629 in words is "twenty-one billion, five hundred seventy-four million, seven hundred seventy-eight thousand, six hundred twenty-nine".