641548381 has 2 divisors, whose sum is σ = 641548382. Its totient is φ = 641548380.

The previous prime is 641548333. The next prime is 641548399. The reversal of 641548381 is 183845146.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 480004281 + 161544100 = 21909^2 + 12710^2 .

It is a cyclic number.

It is not a de Polignac number, because 641548381 - 2⁷ = 641548253 is a prime.

It is a super-2 number, since 2×641548381² = 823168650327442322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (641548301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320774190 + 320774191.

It is an arithmetic number, because the mean of its divisors is an integer number (320774191).

Almost surely, 2^641548381 is an apocalyptic number.

It is an amenable number.

641548381 is a deficient number, since it is larger than the sum of its proper divisors (1).

641548381 is an equidigital number, since it uses as much as digits as its factorization.

641548381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 92160, while the sum is 40.

The square root of 641548381 is about 25328.8053606956. The cubic root of 641548381 is about 862.4682924982.

The spelling of 641548381 in words is "six hundred forty-one million, five hundred forty-eight thousand, three hundred eighty-one".