662851661 has 2 divisors, whose sum is σ = 662851662. Its totient is φ = 662851660.

The previous prime is 662851643. The next prime is 662851691. The reversal of 662851661 is 166158266.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 569729161 + 93122500 = 23869^2 + 9650^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-662851661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (662851601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 331425830 + 331425831.

It is an arithmetic number, because the mean of its divisors is an integer number (331425831).

Almost surely, 2^662851661 is an apocalyptic number.

It is an amenable number.

662851661 is a deficient number, since it is larger than the sum of its proper divisors (1).

662851661 is an equidigital number, since it uses as much as digits as its factorization.

662851661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 41.

The square root of 662851661 is about 25745.9057133362. The cubic root of 662851661 is about 871.9109187996.

The spelling of 662851661 in words is "six hundred sixty-two million, eight hundred fifty-one thousand, six hundred sixty-one".