1659922681 has 2 divisors, whose sum is σ = 1659922682. Its totient is φ = 1659922680.

The previous prime is 1659922661. The next prime is 1659922757. The reversal of 1659922681 is 1862299561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 905047056 + 754875625 = 30084^2 + 27475^2 .

It is a cyclic number.

It is not a de Polignac number, because 1659922681 - 2⁷ = 1659922553 is a prime.

It is a super-2 number, since 2×1659922681² = 5510686613796455522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1659922661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 829961340 + 829961341.

It is an arithmetic number, because the mean of its divisors is an integer number (829961341).

Almost surely, 2^1659922681 is an apocalyptic number.

It is an amenable number.

1659922681 is a deficient number, since it is larger than the sum of its proper divisors (1).

1659922681 is an equidigital number, since it uses as much as digits as its factorization.

1659922681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 466560, while the sum is 49.

The square root of 1659922681 is about 40742.1487037687. The cubic root of 1659922681 is about 1184.0297638401.

The spelling of 1659922681 in words is "one billion, six hundred fifty-nine million, nine hundred twenty-two thousand, six hundred eighty-one".