1626125981 has 2 divisors, whose sum is σ = 1626125982. Its totient is φ = 1626125980.

The previous prime is 1626125971. The next prime is 1626125989. The reversal of 1626125981 is 1895216261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1624896100 + 1229881 = 40310^2 + 1109^2 .

It is a cyclic number.

It is not a de Polignac number, because 1626125981 - 2¹⁰ = 1626124957 is a prime.

It is a super-2 number, since 2×1626125981² = 5288571412166424722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1626125989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 813062990 + 813062991.

It is an arithmetic number, because the mean of its divisors is an integer number (813062991).

Almost surely, 2^1626125981 is an apocalyptic number.

It is an amenable number.

1626125981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1626125981 is an equidigital number, since it uses as much as digits as its factorization.

1626125981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51840, while the sum is 41.

The square root of 1626125981 is about 40325.2523984662. The cubic root of 1626125981 is about 1175.9388255948.

The spelling of 1626125981 in words is "one billion, six hundred twenty-six million, one hundred twenty-five thousand, nine hundred eighty-one".