61665543 has 20 divisors (see below), whose sum is σ = 92797320. Its totient is φ = 40807152.

The previous prime is 61665533. The next prime is 61665557. The reversal of 61665543 is 34556616.

It is not a de Polignac number, because 61665543 - 2⁸ = 61665287 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 61665498 and 61665507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61665503) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 8521 + ... + 13997.

It is an arithmetic number, because the mean of its divisors is an integer number (4639866).

Almost surely, 2^61665543 is an apocalyptic number.

61665543 is a deficient number, since it is larger than the sum of its proper divisors (31131777).

61665543 is a wasteful number, since it uses less digits than its factorization.

61665543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5628 (or 5619 counting only the distinct ones).

The product of its digits is 64800, while the sum is 36.

The square root of 61665543 is about 7852.7411137768. The cubic root of 61665543 is about 395.0761867678.

The spelling of 61665543 in words is "sixty-one million, six hundred sixty-five thousand, five hundred forty-three".