61380781 has 24 divisors (see below), whose sum is σ = 78369984. Its totient is φ = 47537280.

The previous prime is 61380779. The next prime is 61380799. The reversal of 61380781 is 18708316.

61380781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 61380781 - 2¹ = 61380779 is a prime.

It is a super-2 number, since 2×61380781² = 7535200552339922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61380581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 141541 + ... + 141973.

It is an arithmetic number, because the mean of its divisors is an integer number (3265416).

Almost surely, 2^61380781 is an apocalyptic number.

It is an amenable number.

61380781 is a deficient number, since it is larger than the sum of its proper divisors (16989203).

61380781 is a wasteful number, since it uses less digits than its factorization.

61380781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 721 (or 714 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 34.

The square root of 61380781 is about 7834.5887575545. The cubic root of 61380781 is about 394.4671145662.

The spelling of 61380781 in words is "sixty-one million, three hundred eighty thousand, seven hundred eighty-one".