61018729 has 8 divisors (see below), whose sum is σ = 65494440. Its totient is φ = 56641536.

The previous prime is 61018721. The next prime is 61018751. The reversal of 61018729 is 92781016.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 23503104 + 37515625 = 4848^2 + 6125^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 61018729 - 2³ = 61018721 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 61018694 and 61018703.

It is not an unprimeable number, because it can be changed into a prime (61018721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23344 + ... + 25825.

It is an arithmetic number, because the mean of its divisors is an integer number (8186805).

Almost surely, 2^61018729 is an apocalyptic number.

It is an amenable number.

61018729 is a deficient number, since it is larger than the sum of its proper divisors (4475711).

61018729 is a wasteful number, since it uses less digits than its factorization.

61018729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49259.

The product of its (nonzero) digits is 6048, while the sum is 34.

The square root of 61018729 is about 7811.4485852497. The cubic root of 61018729 is about 393.6900019777.

The spelling of 61018729 in words is "sixty-one million, eighteen thousand, seven hundred twenty-nine".