1641313721 has 2 divisors, whose sum is σ = 1641313722. Its totient is φ = 1641313720.

The previous prime is 1641313691. The next prime is 1641313753. The reversal of 1641313721 is 1273131461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1610898496 + 30415225 = 40136^2 + 5515^2 .

It is a cyclic number.

It is not a de Polignac number, because 1641313721 - 2²² = 1637119417 is a prime.

It is not a weakly prime, because it can be changed into another prime (1641313781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820656860 + 820656861.

It is an arithmetic number, because the mean of its divisors is an integer number (820656861).

Almost surely, 2^1641313721 is an apocalyptic number.

It is an amenable number.

1641313721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1641313721 is an equidigital number, since it uses as much as digits as its factorization.

1641313721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3024, while the sum is 29.

The square root of 1641313721 is about 40513.1302295935. The cubic root of 1641313721 is about 1179.5885094468.

The spelling of 1641313721 in words is "one billion, six hundred forty-one million, three hundred thirteen thousand, seven hundred twenty-one".