61057861781 has 8 divisors (see below), whose sum is σ = 71482375104. Its totient is φ = 51058838880.

The previous prime is 61057861747. The next prime is 61057861807. The reversal of 61057861781 is 18716875016.

It is a happy number.

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

It is not a de Polignac number, because 61057861781 - 2³⁴ = 43877992597 is a prime.

It is a super-2 number, since 2×61057861781² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61057860781) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 106372295 + ... + 106372868.

It is an arithmetic number, because the mean of its divisors is an integer number (8935296888).

Almost surely, 2^61057861781 is an apocalyptic number.

It is an amenable number.

61057861781 is a deficient number, since it is larger than the sum of its proper divisors (10424513323).

61057861781 is a wasteful number, since it uses less digits than its factorization.

61057861781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212745211.

The product of its (nonzero) digits is 564480, while the sum is 50.

The spelling of 61057861781 in words is "sixty-one billion, fifty-seven million, eight hundred sixty-one thousand, seven hundred eighty-one".