21604060349 has 2 divisors, whose sum is σ = 21604060350. Its totient is φ = 21604060348.

The previous prime is 21604060273. The next prime is 21604060369. The reversal of 21604060349 is 94306040612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21445552249 + 158508100 = 146443^2 + 12590^2 .

It is a cyclic number.

It is not a de Polignac number, because 21604060349 - 2¹⁶ = 21603994813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21604060369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10802030174 + 10802030175.

It is an arithmetic number, because the mean of its divisors is an integer number (10802030175).

Almost surely, 2^21604060349 is an apocalyptic number.

It is an amenable number.

21604060349 is a deficient number, since it is larger than the sum of its proper divisors (1).

21604060349 is an equidigital number, since it uses as much as digits as its factorization.

21604060349 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 35.

The spelling of 21604060349 in words is "twenty-one billion, six hundred four million, sixty thousand, three hundred forty-nine".