21471464317649 has 2 divisors, whose sum is σ = 21471464317650. Its totient is φ = 21471464317648.

The previous prime is 21471464317579. The next prime is 21471464317657. The reversal of 21471464317649 is 94671346417412.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11678520238225 + 9792944079424 = 3417385^2 + 3129368^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21471464317649 is a prime.

It is a super-2 number, since 2×21471464317649² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21471464317249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10735732158824 + 10735732158825.

It is an arithmetic number, because the mean of its divisors is an integer number (10735732158825).

Almost surely, 2^{21471464317649} is an apocalyptic number.

It is an amenable number.

21471464317649 is a deficient number, since it is larger than the sum of its proper divisors (1).

21471464317649 is an equidigital number, since it uses as much as digits as its factorization.

21471464317649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24385536, while the sum is 59.

The spelling of 21471464317649 in words is "twenty-one trillion, four hundred seventy-one billion, four hundred sixty-four million, three hundred seventeen thousand, six hundred forty-nine".