1506131981 has 2 divisors, whose sum is σ = 1506131982. Its totient is φ = 1506131980.

The previous prime is 1506131971. The next prime is 1506132011. The reversal of 1506131981 is 1891316051.

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., 835788100 + 670343881 = 28910^2 + 25891^2 .

It is an emirp because it is prime and its reverse (1891316051) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1506131981 - 2⁶ = 1506131917 is a prime.

It is a super-2 number, since 2×1506131981² = 4536867088381968722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1506131941) 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, 753065990 + 753065991.

It is an arithmetic number, because the mean of its divisors is an integer number (753065991).

Almost surely, 2^1506131981 is an apocalyptic number.

It is an amenable number.

1506131981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1506131981 is an equidigital number, since it uses as much as digits as its factorization.

1506131981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6480, while the sum is 35.

The square root of 1506131981 is about 38808.9162564481. The cubic root of 1506131981 is about 1146.2719809141.

The spelling of 1506131981 in words is "one billion, five hundred six million, one hundred thirty-one thousand, nine hundred eighty-one".