783121 has 2 divisors, whose sum is σ = 783122. Its totient is φ = 783120.

The previous prime is 783119. The next prime is 783131. The reversal of 783121 is 121387.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 440896 + 342225 = 664^2 + 585^2 .

It is a cyclic number.

It is not a de Polignac number, because 783121 - 2¹ = 783119 is a prime.

It is a super-2 number, since 2×783121² = 1226557001282, which contains 22 as substring.

Together with 783119, it forms a pair of twin primes.

783121 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 783092 and 783101.

It is not a weakly prime, because it can be changed into another prime (783131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 391560 + 391561.

It is an arithmetic number, because the mean of its divisors is an integer number (391561).

2⁷⁸³¹²¹ is an apocalyptic number.

It is an amenable number.

783121 is a deficient number, since it is larger than the sum of its proper divisors (1).

783121 is an equidigital number, since it uses as much as digits as its factorization.

783121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 336, while the sum is 22.

The square root of 783121 is about 884.9412409872. The cubic root of 783121 is about 92.1742522953.

It can be divided in two parts, 7831 and 21, that multiplied together give a triangular number (164451 = T₅₇₃).

The spelling of 783121 in words is "seven hundred eighty-three thousand, one hundred twenty-one".