6431407343521 has 2 divisors, whose sum is σ = 6431407343522. Its totient is φ = 6431407343520.

The previous prime is 6431407343489. The next prime is 6431407343567. The reversal of 6431407343521 is 1253437041346.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3302361217600 + 3129046125921 = 1817240^2 + 1768911^2 .

It is a cyclic number.

It is not a de Polignac number, because 6431407343521 - 2⁵ = 6431407343489 is a prime.

It is a super-2 number, since 2×6431407343521² (a number of 26 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (6431407343321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3215703671760 + 3215703671761.

It is an arithmetic number, because the mean of its divisors is an integer number (3215703671761).

Almost surely, 2^{6431407343521} is an apocalyptic number.

It is an amenable number.

6431407343521 is a deficient number, since it is larger than the sum of its proper divisors (1).

6431407343521 is an equidigital number, since it uses as much as digits as its factorization.

6431407343521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 725760, while the sum is 43.

The spelling of 6431407343521 in words is "six trillion, four hundred thirty-one billion, four hundred seven million, three hundred forty-three thousand, five hundred twenty-one".