55781061 has 32 divisors (see below), whose sum is σ = 87552000. Its totient is φ = 31575600.

The previous prime is 55781009. The next prime is 55781071. The reversal of 55781061 is 16018755.

55781061 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 55781061 - 2¹⁵ = 55748293 is a prime.

It is a super-2 number, since 2×55781061² = 6223053532571442, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55781071) 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 31 ways as a sum of consecutive naturals, for example, 155200 + ... + 155558.

It is an arithmetic number, because the mean of its divisors is an integer number (2736000).

Almost surely, 2^55781061 is an apocalyptic number.

It is an amenable number.

55781061 is a deficient number, since it is larger than the sum of its proper divisors (31770939).

55781061 is a wasteful number, since it uses less digits than its factorization.

55781061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 534 (or 520 counting only the distinct ones).

The product of its (nonzero) digits is 8400, while the sum is 33.

The square root of 55781061 is about 7468.6719703037. The cubic root of 55781061 is about 382.0869958017.

It can be divided in two parts, 557 and 81061, that added together give a palindrome (81618).

The spelling of 55781061 in words is "fifty-five million, seven hundred eighty-one thousand, sixty-one".