61780730 has 64 divisors (see below), whose sum is σ = 127370880. Its totient is φ = 21369600.

The previous prime is 61780711. The next prime is 61780753. The reversal of 61780730 is 3708716.

It is a happy number.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 341240 + ... + 341420.

It is an arithmetic number, because the mean of its divisors is an integer number (1990170).

Almost surely, 2^61780730 is an apocalyptic number.

61780730 is an abundant number, since it is smaller than the sum of its proper divisors (65590150).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61780730 is a wasteful number, since it uses less digits than its factorization.

61780730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 335.

The product of its (nonzero) digits is 7056, while the sum is 32.

The square root of 61780730 is about 7860.0718826230. The cubic root of 61780730 is about 395.3220254908.

The spelling of 61780730 in words is "sixty-one million, seven hundred eighty thousand, seven hundred thirty".