61575943781 has 16 divisors (see below), whose sum is σ = 70295299200. Its totient is φ = 53390800320.

The previous prime is 61575943771. The next prime is 61575943783. The reversal of 61575943781 is 18734957516.

It is a happy number.

It is not a de Polignac number, because 61575943781 - 2²⁶ = 61508834917 is a prime.

It is a super-2 number, since 2×61575943781² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61575943783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 260390 + ... + 436983.

It is an arithmetic number, because the mean of its divisors is an integer number (4393456200).

Almost surely, 2^61575943781 is an apocalyptic number.

It is an amenable number.

61575943781 is a deficient number, since it is larger than the sum of its proper divisors (8719355419).

61575943781 is a wasteful number, since it uses less digits than its factorization.

61575943781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 697756.

The product of its digits is 6350400, while the sum is 56.

The spelling of 61575943781 in words is "sixty-one billion, five hundred seventy-five million, nine hundred forty-three thousand, seven hundred eighty-one".