1957981 has 2 divisors, whose sum is σ = 1957982. Its totient is φ = 1957980.

The previous prime is 1957957. The next prime is 1957997. The reversal of 1957981 is 1897591.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1301881 + 656100 = 1141^2 + 810^2 .

It is a cyclic number.

It is not a de Polignac number, because 1957981 - 2⁷ = 1957853 is a prime.

It is a super-2 number, since 2×1957981² = 7667379192722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1952981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 978990 + 978991.

It is an arithmetic number, because the mean of its divisors is an integer number (978991).

2^1957981 is an apocalyptic number.

It is an amenable number.

1957981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1957981 is an equidigital number, since it uses as much as digits as its factorization.

1957981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22680, while the sum is 40.

The square root of 1957981 is about 1399.2787427814. The cubic root of 1957981 is about 125.1035089302.

The spelling of 1957981 in words is "one million, nine hundred fifty-seven thousand, nine hundred eighty-one".