642633541 has 12 divisors (see below), whose sum is σ = 747919116. Its totient is φ = 549845120.

The previous prime is 642633529. The next prime is 642633571. The reversal of 642633541 is 145336246.

It can be written as a sum of positive squares in 2 ways, for example, as 327429025 + 315204516 = 18095^2 + 17754^2 .

It is not a de Polignac number, because 642633541 - 2⁷ = 642633413 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 642633497 and 642633506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642633571) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 154150 + ... + 158263.

It is an arithmetic number, because the mean of its divisors is an integer number (62326593).

Almost surely, 2^642633541 is an apocalyptic number.

It is an amenable number.

642633541 is a deficient number, since it is larger than the sum of its proper divisors (105285575).

642633541 is a wasteful number, since it uses less digits than its factorization.

642633541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 312452 (or 312441 counting only the distinct ones).

The product of its digits is 51840, while the sum is 34.

The square root of 642633541 is about 25350.2177702678. The cubic root of 642633541 is about 862.9542983988.

Adding to 642633541 its reverse (145336246), we get a palindrome (787969787).

The spelling of 642633541 in words is "six hundred forty-two million, six hundred thirty-three thousand, five hundred forty-one".