819157649 has 2 divisors, whose sum is σ = 819157650. Its totient is φ = 819157648.

The previous prime is 819157643. The next prime is 819157667. The reversal of 819157649 is 946751918.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 642267649 + 176890000 = 25343^2 + 13300^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-819157649 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 819157597 and 819157606.

It is not a weakly prime, because it can be changed into another prime (819157643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 409578824 + 409578825.

It is an arithmetic number, because the mean of its divisors is an integer number (409578825).

Almost surely, 2^819157649 is an apocalyptic number.

It is an amenable number.

819157649 is a deficient number, since it is larger than the sum of its proper divisors (1).

819157649 is an equidigital number, since it uses as much as digits as its factorization.

819157649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 544320, while the sum is 50.

The square root of 819157649 is about 28620.9302609122. The cubic root of 819157649 is about 935.6695515915.

The spelling of 819157649 in words is "eight hundred nineteen million, one hundred fifty-seven thousand, six hundred forty-nine".