862009661 has 2 divisors, whose sum is σ = 862009662. Its totient is φ = 862009660.

The previous prime is 862009639. The next prime is 862009699. The reversal of 862009661 is 166900268.

It is an a-pointer prime, because the next prime (862009699) can be obtained adding 862009661 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 459244900 + 402764761 = 21430^2 + 20069^2 .

It is a cyclic number.

It is not a de Polignac number, because 862009661 - 2⁶ = 862009597 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (862003661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 431004830 + 431004831.

It is an arithmetic number, because the mean of its divisors is an integer number (431004831).

Almost surely, 2^862009661 is an apocalyptic number.

It is an amenable number.

862009661 is a deficient number, since it is larger than the sum of its proper divisors (1).

862009661 is an equidigital number, since it uses as much as digits as its factorization.

862009661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 38.

The square root of 862009661 is about 29360.0010388283. The cubic root of 862009661 is about 951.7087109458.

The spelling of 862009661 in words is "eight hundred sixty-two million, nine thousand, six hundred sixty-one".