21547557347 has 2 divisors, whose sum is σ = 21547557348. Its totient is φ = 21547557346.

The previous prime is 21547557331. The next prime is 21547557359. The reversal of 21547557347 is 74375574512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21547557347 - 2⁴ = 21547557331 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21547557295 and 21547557304.

It is not a weakly prime, because it can be changed into another prime (21547557047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10773778673 + 10773778674.

It is an arithmetic number, because the mean of its divisors is an integer number (10773778674).

Almost surely, 2^21547557347 is an apocalyptic number.

21547557347 is a deficient number, since it is larger than the sum of its proper divisors (1).

21547557347 is an equidigital number, since it uses as much as digits as its factorization.

21547557347 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4116000, while the sum is 50.

The spelling of 21547557347 in words is "twenty-one billion, five hundred forty-seven million, five hundred fifty-seven thousand, three hundred forty-seven".