686362121 has 2 divisors, whose sum is σ = 686362122. Its totient is φ = 686362120.

The previous prime is 686362069. The next prime is 686362139. The reversal of 686362121 is 121263686.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 543822400 + 142539721 = 23320^2 + 11939^2 .

It is a cyclic number.

It is not a de Polignac number, because 686362121 - 2²² = 682167817 is a prime.

It is a super-2 number, since 2×686362121² = 942185922287237282, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (686362141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343181060 + 343181061.

It is an arithmetic number, because the mean of its divisors is an integer number (343181061).

Almost surely, 2^686362121 is an apocalyptic number.

It is an amenable number.

686362121 is a deficient number, since it is larger than the sum of its proper divisors (1).

686362121 is an equidigital number, since it uses as much as digits as its factorization.

686362121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 35.

The square root of 686362121 is about 26198.5137173848. The cubic root of 686362121 is about 882.0998926184.

The spelling of 686362121 in words is "six hundred eighty-six million, three hundred sixty-two thousand, one hundred twenty-one".