1706651621 has 2 divisors, whose sum is σ = 1706651622. Its totient is φ = 1706651620.

The previous prime is 1706651581. The next prime is 1706651623. The reversal of 1706651621 is 1261566071.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1706598721 + 52900 = 41311^2 + 230^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1706651621 is a prime.

Together with 1706651623, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1706651623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 853325810 + 853325811.

It is an arithmetic number, because the mean of its divisors is an integer number (853325811).

Almost surely, 2^1706651621 is an apocalyptic number.

It is an amenable number.

1706651621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1706651621 is an equidigital number, since it uses as much as digits as its factorization.

1706651621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 1706651621 is about 41311.6402603431. The cubic root of 1706651621 is about 1195.0377539819.

The spelling of 1706651621 in words is "one billion, seven hundred six million, six hundred fifty-one thousand, six hundred twenty-one".