21447253097 has 2 divisors, whose sum is σ = 21447253098. Its totient is φ = 21447253096.

The previous prime is 21447253081. The next prime is 21447253111. The reversal of 21447253097 is 79035274412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21427397161 + 19855936 = 146381^2 + 4456^2 .

It is a cyclic number.

It is not a de Polignac number, because 21447253097 - 2⁴ = 21447253081 is a prime.

It is not a weakly prime, because it can be changed into another prime (21447253027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10723626548 + 10723626549.

It is an arithmetic number, because the mean of its divisors is an integer number (10723626549).

Almost surely, 2^21447253097 is an apocalyptic number.

It is an amenable number.

21447253097 is a deficient number, since it is larger than the sum of its proper divisors (1).

21447253097 is an equidigital number, since it uses as much as digits as its factorization.

21447253097 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 423360, while the sum is 44.

The spelling of 21447253097 in words is "twenty-one billion, four hundred forty-seven million, two hundred fifty-three thousand, ninety-seven".