861645457 has 2 divisors, whose sum is σ = 861645458. Its totient is φ = 861645456.

The previous prime is 861645451. The next prime is 861645461. The reversal of 861645457 is 754546168.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 540841536 + 320803921 = 23256^2 + 17911^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-861645457 is a prime.

It is not a weakly prime, because it can be changed into another prime (861645451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 430822728 + 430822729.

It is an arithmetic number, because the mean of its divisors is an integer number (430822729).

Almost surely, 2^861645457 is an apocalyptic number.

It is an amenable number.

861645457 is a deficient number, since it is larger than the sum of its proper divisors (1).

861645457 is an equidigital number, since it uses as much as digits as its factorization.

861645457 is an evil number, because the sum of its binary digits is even.

The product of its digits is 806400, while the sum is 46.

The square root of 861645457 is about 29353.7979995775. The cubic root of 861645457 is about 951.5746579445.

The spelling of 861645457 in words is "eight hundred sixty-one million, six hundred forty-five thousand, four hundred fifty-seven".