840427457 has 2 divisors, whose sum is σ = 840427458. Its totient is φ = 840427456.

The previous prime is 840427451. The next prime is 840427477. The reversal of 840427457 is 754724048.

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., 613503361 + 226924096 = 24769^2 + 15064^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-840427457 is a prime.

It is not a weakly prime, because it can be changed into another prime (840427451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 420213728 + 420213729.

It is an arithmetic number, because the mean of its divisors is an integer number (420213729).

Almost surely, 2^840427457 is an apocalyptic number.

It is an amenable number.

840427457 is a deficient number, since it is larger than the sum of its proper divisors (1).

840427457 is an equidigital number, since it uses as much as digits as its factorization.

840427457 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 250880, while the sum is 41.

The square root of 840427457 is about 28990.1268883046. The cubic root of 840427457 is about 943.6988174397.

The spelling of 840427457 in words is "eight hundred forty million, four hundred twenty-seven thousand, four hundred fifty-seven".