21161002251097 has 2 divisors, whose sum is σ = 21161002251098. Its totient is φ = 21161002251096.

The previous prime is 21161002251061. The next prime is 21161002251139. The reversal of 21161002251097 is 79015220016112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18247754084121 + 2913248166976 = 4271739^2 + 1706824^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21161002251097 is a prime.

It is not a weakly prime, because it can be changed into another prime (21161002257097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10580501125548 + 10580501125549.

It is an arithmetic number, because the mean of its divisors is an integer number (10580501125549).

Almost surely, 2^{21161002251097} is an apocalyptic number.

It is an amenable number.

21161002251097 is a deficient number, since it is larger than the sum of its proper divisors (1).

21161002251097 is an equidigital number, since it uses as much as digits as its factorization.

21161002251097 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15120, while the sum is 37.

The spelling of 21161002251097 in words is "twenty-one trillion, one hundred sixty-one billion, two million, two hundred fifty-one thousand, ninety-seven".