686372191061 has 2 divisors, whose sum is σ = 686372191062. Its totient is φ = 686372191060.

The previous prime is 686372191019. The next prime is 686372191091. The reversal of 686372191061 is 160191273686.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 547918246225 + 138453944836 = 740215^2 + 372094^2 .

It is a cyclic number.

It is not a de Polignac number, because 686372191061 - 2²² = 686367996757 is a prime.

It is a super-2 number, since 2×686372191061² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (686372191091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343186095530 + 343186095531.

It is an arithmetic number, because the mean of its divisors is an integer number (343186095531).

Almost surely, 2^686372191061 is an apocalyptic number.

It is an amenable number.

686372191061 is a deficient number, since it is larger than the sum of its proper divisors (1).

686372191061 is an equidigital number, since it uses as much as digits as its factorization.

686372191061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 653184, while the sum is 50.

The spelling of 686372191061 in words is "six hundred eighty-six billion, three hundred seventy-two million, one hundred ninety-one thousand, sixty-one".