1958681 has 2 divisors, whose sum is σ = 1958682. Its totient is φ = 1958680.

The previous prime is 1958651. The next prime is 1958683. The reversal of 1958681 is 1868591.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1177225 + 781456 = 1085^2 + 884^2 .

It is an emirp because it is prime and its reverse (1868591) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1958681 - 2⁶ = 1958617 is a prime.

It is a super-2 number, since 2×1958681² = 7672862519522, which contains 22 as substring.

Together with 1958683, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1958683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 979340 + 979341.

It is an arithmetic number, because the mean of its divisors is an integer number (979341).

2^1958681 is an apocalyptic number.

It is an amenable number.

1958681 is a deficient number, since it is larger than the sum of its proper divisors (1).

1958681 is an equidigital number, since it uses as much as digits as its factorization.

1958681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17280, while the sum is 38.

The square root of 1958681 is about 1399.5288492918. The cubic root of 1958681 is about 125.1184157862.

The spelling of 1958681 in words is "one million, nine hundred fifty-eight thousand, six hundred eighty-one".