1313506021 has 2 divisors, whose sum is σ = 1313506022. Its totient is φ = 1313506020.

The previous prime is 1313506013. The next prime is 1313506027. The reversal of 1313506021 is 1206053131.

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., 1268428225 + 45077796 = 35615^2 + 6714^2 .

It is a cyclic number.

It is not a de Polignac number, because 1313506021 - 2³ = 1313506013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1313505983 and 1313506001.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1313506027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 656753010 + 656753011.

It is an arithmetic number, because the mean of its divisors is an integer number (656753011).

Almost surely, 2^1313506021 is an apocalyptic number.

It is an amenable number.

1313506021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1313506021 is an equidigital number, since it uses as much as digits as its factorization.

1313506021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 540, while the sum is 22.

The square root of 1313506021 is about 36242.3236148015. The cubic root of 1313506021 is about 1095.1594524647.

Adding to 1313506021 its reverse (1206053131), we get a palindrome (2519559152).

The spelling of 1313506021 in words is "one billion, three hundred thirteen million, five hundred six thousand, twenty-one".