42655641521 has 2 divisors, whose sum is σ = 42655641522. Its totient is φ = 42655641520.

The previous prime is 42655641499. The next prime is 42655641557. The reversal of 42655641521 is 12514655624.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21850752400 + 20804889121 = 147820^2 + 144239^2 .

It is a cyclic number.

It is not a de Polignac number, because 42655641521 - 2¹⁴ = 42655625137 is a prime.

It is not a weakly prime, because it can be changed into another prime (42655641221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21327820760 + 21327820761.

It is an arithmetic number, because the mean of its divisors is an integer number (21327820761).

Almost surely, 2^42655641521 is an apocalyptic number.

It is an amenable number.

42655641521 is a deficient number, since it is larger than the sum of its proper divisors (1).

42655641521 is an equidigital number, since it uses as much as digits as its factorization.

42655641521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 288000, while the sum is 41.

The spelling of 42655641521 in words is "forty-two billion, six hundred fifty-five million, six hundred forty-one thousand, five hundred twenty-one".