1505723981 has 2 divisors, whose sum is σ = 1505723982. Its totient is φ = 1505723980.

The previous prime is 1505723969. The next prime is 1505724019. The reversal of 1505723981 is 1893275051.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1433303881 + 72420100 = 37859^2 + 8510^2 .

It is an emirp because it is prime and its reverse (1893275051) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1505723981 - 2²⁶ = 1438615117 is a prime.

It is a super-2 number, since 2×1505723981² = 4534409413916976722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1505723941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 752861990 + 752861991.

It is an arithmetic number, because the mean of its divisors is an integer number (752861991).

Almost surely, 2^1505723981 is an apocalyptic number.

It is an amenable number.

1505723981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1505723981 is an equidigital number, since it uses as much as digits as its factorization.

1505723981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 75600, while the sum is 41.

The square root of 1505723981 is about 38803.6593764042. The cubic root of 1505723981 is about 1146.1684660361.

The spelling of 1505723981 in words is "one billion, five hundred five million, seven hundred twenty-three thousand, nine hundred eighty-one".