644057541 has 16 divisors (see below), whose sum is σ = 955204800. Its totient is φ = 428901264.

The previous prime is 644057527. The next prime is 644057567. The reversal of 644057541 is 145750446.

644057541 is a `hidden beast` number, since 6 + 4 + 40 + 575 + 41 = 666.

It is not a de Polignac number, because 644057541 - 2⁵ = 644057509 is a prime.

It is a super-2 number, since 2×644057541² = 829620232237933362, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 644057496 and 644057505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644057521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12975 + ... + 38163.

It is an arithmetic number, because the mean of its divisors is an integer number (59700300).

Almost surely, 2^644057541 is an apocalyptic number.

It is an amenable number.

644057541 is a deficient number, since it is larger than the sum of its proper divisors (311147259).

644057541 is a wasteful number, since it uses less digits than its factorization.

644057541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26145 (or 26139 counting only the distinct ones).

The product of its (nonzero) digits is 67200, while the sum is 36.

The square root of 644057541 is about 25378.2887720981. The cubic root of 644057541 is about 863.5912297646.

The spelling of 644057541 in words is "six hundred forty-four million, fifty-seven thousand, five hundred forty-one".