521420420642531 has 2 divisors, whose sum is σ = 521420420642532. Its totient is φ = 521420420642530.

The previous prime is 521420420642521. The next prime is 521420420642603. The reversal of 521420420642531 is 135246024024125.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 521420420642531 - 2⁶ = 521420420642467 is a prime.

It is a super-2 number, since 2×521420420642531² (a number of 30 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (521420420642521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260710210321265 + 260710210321266.

It is an arithmetic number, because the mean of its divisors is an integer number (260710210321266).

Almost surely, 2^{521420420642531} is an apocalyptic number.

521420420642531 is a deficient number, since it is larger than the sum of its proper divisors (1).

521420420642531 is an equidigital number, since it uses as much as digits as its factorization.

521420420642531 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 460800, while the sum is 41.

Adding to 521420420642531 its reverse (135246024024125), we get a palindrome (656666444666656).

The spelling of 521420420642531 in words is "five hundred twenty-one trillion, four hundred twenty billion, four hundred twenty million, six hundred forty-two thousand, five hundred thirty-one".