731776561 has 2 divisors, whose sum is σ = 731776562. Its totient is φ = 731776560.

The previous prime is 731776553. The next prime is 731776627. The reversal of 731776561 is 165677137.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 569061025 + 162715536 = 23855^2 + 12756^2 .

It is a cyclic number.

It is not a de Polignac number, because 731776561 - 2³ = 731776553 is a prime.

It is not a weakly prime, because it can be changed into another prime (731776501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 365888280 + 365888281.

It is an arithmetic number, because the mean of its divisors is an integer number (365888281).

Almost surely, 2^731776561 is an apocalyptic number.

It is an amenable number.

731776561 is a deficient number, since it is larger than the sum of its proper divisors (1).

731776561 is an equidigital number, since it uses as much as digits as its factorization.

731776561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 185220, while the sum is 43.

The square root of 731776561 is about 27051.3689302409. The cubic root of 731776561 is about 901.1411701181.

The spelling of 731776561 in words is "seven hundred thirty-one million, seven hundred seventy-six thousand, five hundred sixty-one".