1630440821 has 2 divisors, whose sum is σ = 1630440822. Its totient is φ = 1630440820.

The previous prime is 1630440739. The next prime is 1630440827. The reversal of 1630440821 is 1280440361.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1629736900 + 703921 = 40370^2 + 839^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1630440821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1630440827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 815220410 + 815220411.

It is an arithmetic number, because the mean of its divisors is an integer number (815220411).

Almost surely, 2^1630440821 is an apocalyptic number.

It is an amenable number.

1630440821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1630440821 is an equidigital number, since it uses as much as digits as its factorization.

1630440821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 1630440821 is about 40378.7174263869. The cubic root of 1630440821 is about 1176.9780043325.

The spelling of 1630440821 in words is "one billion, six hundred thirty million, four hundred forty thousand, eight hundred twenty-one".