738561781 has 2 divisors, whose sum is σ = 738561782. Its totient is φ = 738561780.

The previous prime is 738561643. The next prime is 738561881. The reversal of 738561781 is 187165837.

738561781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 688222756 + 50339025 = 26234^2 + 7095^2 .

It is a cyclic number.

It is not a de Polignac number, because 738561781 - 2¹⁹ = 738037493 is a prime.

It is a super-2 number, since 2×738561781² = 1090947008707783922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (738561281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 369280890 + 369280891.

It is an arithmetic number, because the mean of its divisors is an integer number (369280891).

Almost surely, 2^738561781 is an apocalyptic number.

It is an amenable number.

738561781 is a deficient number, since it is larger than the sum of its proper divisors (1).

738561781 is an equidigital number, since it uses as much as digits as its factorization.

738561781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 282240, while the sum is 46.

The square root of 738561781 is about 27176.4931696494. The cubic root of 738561781 is about 903.9178098489.

The spelling of 738561781 in words is "seven hundred thirty-eight million, five hundred sixty-one thousand, seven hundred eighty-one".