641354521 has 2 divisors, whose sum is σ = 641354522. Its totient is φ = 641354520.

The previous prime is 641354491. The next prime is 641354543. The reversal of 641354521 is 125453146.

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., 635594521 + 5760000 = 25211^2 + 2400^2 .

It is a cyclic number.

It is not a de Polignac number, because 641354521 - 2⁵ = 641354489 is a prime.

It is a super-2 number, since 2×641354521² = 822671243214278882, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (641354561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320677260 + 320677261.

It is an arithmetic number, because the mean of its divisors is an integer number (320677261).

Almost surely, 2^641354521 is an apocalyptic number.

It is an amenable number.

641354521 is a deficient number, since it is larger than the sum of its proper divisors (1).

641354521 is an equidigital number, since it uses as much as digits as its factorization.

641354521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14400, while the sum is 31.

The square root of 641354521 is about 25324.9782033470. The cubic root of 641354521 is about 862.3814115749.

The spelling of 641354521 in words is "six hundred forty-one million, three hundred fifty-four thousand, five hundred twenty-one".