1616856217 has 2 divisors, whose sum is σ = 1616856218. Its totient is φ = 1616856216.

The previous prime is 1616856209. The next prime is 1616856221. The reversal of 1616856217 is 7126586161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1367816256 + 249039961 = 36984^2 + 15781^2 .

It is a cyclic number.

It is not a de Polignac number, because 1616856217 - 2³ = 1616856209 is a prime.

It is a super-2 number, since 2×1616856217² = 5228448052903102178, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1616826217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 808428108 + 808428109.

It is an arithmetic number, because the mean of its divisors is an integer number (808428109).

Almost surely, 2^1616856217 is an apocalyptic number.

It is an amenable number.

1616856217 is a deficient number, since it is larger than the sum of its proper divisors (1).

1616856217 is an equidigital number, since it uses as much as digits as its factorization.

1616856217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120960, while the sum is 43.

The square root of 1616856217 is about 40210.1506711925. The cubic root of 1616856217 is about 1173.7000785070.

The spelling of 1616856217 in words is "one billion, six hundred sixteen million, eight hundred fifty-six thousand, two hundred seventeen".