1642548521 has 2 divisors, whose sum is σ = 1642548522. Its totient is φ = 1642548520.

The previous prime is 1642548491. The next prime is 1642548533. The reversal of 1642548521 is 1258452461.

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., 1255993600 + 386554921 = 35440^2 + 19661^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1642548521 is a prime.

It is not a weakly prime, because it can be changed into another prime (1642548541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 821274260 + 821274261.

It is an arithmetic number, because the mean of its divisors is an integer number (821274261).

Almost surely, 2^1642548521 is an apocalyptic number.

It is an amenable number.

1642548521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1642548521 is an equidigital number, since it uses as much as digits as its factorization.

1642548521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 76800, while the sum is 38.

The square root of 1642548521 is about 40528.3668681579. The cubic root of 1642548521 is about 1179.8842462820.

It can be divided in two parts, 16425 and 48521, that added together give a palindrome (64946).

The spelling of 1642548521 in words is "one billion, six hundred forty-two million, five hundred forty-eight thousand, five hundred twenty-one".