521540023 has 2 divisors, whose sum is σ = 521540024. Its totient is φ = 521540022.

The previous prime is 521540003. The next prime is 521540029. The reversal of 521540023 is 320045125.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-521540023 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 521539976 and 521540003.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (521540029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260770011 + 260770012.

It is an arithmetic number, because the mean of its divisors is an integer number (260770012).

Almost surely, 2^521540023 is an apocalyptic number.

521540023 is a deficient number, since it is larger than the sum of its proper divisors (1).

521540023 is an equidigital number, since it uses as much as digits as its factorization.

521540023 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 521540023 is about 22837.2507758705. The cubic root of 521540023 is about 804.9382167775.

Adding to 521540023 its reverse (320045125), we get a palindrome (841585148).

The spelling of 521540023 in words is "five hundred twenty-one million, five hundred forty thousand, twenty-three".