738315821 has 2 divisors, whose sum is σ = 738315822. Its totient is φ = 738315820.

The previous prime is 738315817. The next prime is 738315839. The reversal of 738315821 is 128513837.

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., 561026596 + 177289225 = 23686^2 + 13315^2 .

It is an emirp because it is prime and its reverse (128513837) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 738315821 - 2² = 738315817 is a prime.

It is a super-2 number, since 2×738315821² = 1090220503077808082, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (738315841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 369157910 + 369157911.

It is an arithmetic number, because the mean of its divisors is an integer number (369157911).

Almost surely, 2^738315821 is an apocalyptic number.

It is an amenable number.

738315821 is a deficient number, since it is larger than the sum of its proper divisors (1).

738315821 is an equidigital number, since it uses as much as digits as its factorization.

738315821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40320, while the sum is 38.

The square root of 738315821 is about 27171.9675584968. The cubic root of 738315821 is about 903.8174561096.

The spelling of 738315821 in words is "seven hundred thirty-eight million, three hundred fifteen thousand, eight hundred twenty-one".