61728885 has 20 divisors (see below), whose sum is σ = 110655468. Its totient is φ = 32921856.

The previous prime is 61728881. The next prime is 61728911. The reversal of 61728885 is 58882716.

61728885 is a `hidden beast` number, since 617 + 28 + 8 + 8 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 12068676 + 49660209 = 3474^2 + 7047^2 .

It is not a de Polignac number, because 61728885 - 2² = 61728881 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 61728885.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61728881) 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, 75804 + ... + 76613.

Almost surely, 2^61728885 is an apocalyptic number.

It is an amenable number.

61728885 is a deficient number, since it is larger than the sum of its proper divisors (48926583).

61728885 is a wasteful number, since it uses less digits than its factorization.

61728885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152434 (or 152425 counting only the distinct ones).

The product of its digits is 215040, while the sum is 45.

The square root of 61728885 is about 7856.7731926027. The cubic root of 61728885 is about 395.2114127577.

The spelling of 61728885 in words is "sixty-one million, seven hundred twenty-eight thousand, eight hundred eighty-five".