21999830617 has 2 divisors, whose sum is σ = 21999830618. Its totient is φ = 21999830616.

The previous prime is 21999830557. The next prime is 21999830707. The reversal of 21999830617 is 71603899912.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21014561296 + 985269321 = 144964^2 + 31389^2 .

It is a cyclic number.

It is not a de Polignac number, because 21999830617 - 2¹⁵ = 21999797849 is a prime.

It is a super-3 number, since 3×21999830617³ (a number of 32 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (21999830317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10999915308 + 10999915309.

It is an arithmetic number, because the mean of its divisors is an integer number (10999915309).

Almost surely, 2^21999830617 is an apocalyptic number.

It is an amenable number.

21999830617 is a deficient number, since it is larger than the sum of its proper divisors (1).

21999830617 is an equidigital number, since it uses as much as digits as its factorization.

21999830617 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1469664, while the sum is 55.

The spelling of 21999830617 in words is "twenty-one billion, nine hundred ninety-nine million, eight hundred thirty thousand, six hundred seventeen".