1520681 has 2 divisors, whose sum is σ = 1520682. Its totient is φ = 1520680.

The previous prime is 1520653. The next prime is 1520683. The reversal of 1520681 is 1860251.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1478656 + 42025 = 1216^2 + 205^2 .

It is an emirp because it is prime and its reverse (1860251) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1520681 - 2¹⁰ = 1519657 is a prime.

It is a super-2 number, since 2×1520681² = 4624941407522, which contains 22 as substring.

Together with 1520683, 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 (1520683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 760340 + 760341.

It is an arithmetic number, because the mean of its divisors is an integer number (760341).

2^1520681 is an apocalyptic number.

It is an amenable number.

1520681 is a deficient number, since it is larger than the sum of its proper divisors (1).

1520681 is an equidigital number, since it uses as much as digits as its factorization.

1520681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 480, while the sum is 23.

The square root of 1520681 is about 1233.1589516360. The cubic root of 1520681 is about 114.9951100630.

The spelling of 1520681 in words is "one million, five hundred twenty thousand, six hundred eighty-one".