42640504261 has 2 divisors, whose sum is σ = 42640504262. Its totient is φ = 42640504260.

The previous prime is 42640504253. The next prime is 42640504267. The reversal of 42640504261 is 16240504624.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42634403361 + 6100900 = 206481^2 + 2470^2 .

It is a cyclic number.

It is not a de Polignac number, because 42640504261 - 2³ = 42640504253 is a prime.

It is a super-2 number, since 2×42640504261² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42640504267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21320252130 + 21320252131.

It is an arithmetic number, because the mean of its divisors is an integer number (21320252131).

Almost surely, 2^42640504261 is an apocalyptic number.

It is an amenable number.

42640504261 is a deficient number, since it is larger than the sum of its proper divisors (1).

42640504261 is an equidigital number, since it uses as much as digits as its factorization.

42640504261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46080, while the sum is 34.

The spelling of 42640504261 in words is "forty-two billion, six hundred forty million, five hundred four thousand, two hundred sixty-one".