61881881 has 4 divisors (see below), whose sum is σ = 62729652. Its totient is φ = 61034112.

The previous prime is 61881863. The next prime is 61881901. The reversal of 61881881 is 18818816.

61881881 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 51609856 + 10272025 = 7184^2 + 3205^2 .

It is a cyclic number.

It is not a de Polignac number, because 61881881 - 2²² = 57687577 is a prime.

It is a super-2 number, since 2×61881881² = 7658734392196322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61881821) 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 3 ways as a sum of consecutive naturals, for example, 423776 + ... + 423921.

It is an arithmetic number, because the mean of its divisors is an integer number (15682413).

Almost surely, 2^61881881 is an apocalyptic number.

It is an amenable number.

61881881 is a deficient number, since it is larger than the sum of its proper divisors (847771).

61881881 is an equidigital number, since it uses as much as digits as its factorization.

61881881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 847770.

The product of its digits is 24576, while the sum is 41.

The square root of 61881881 is about 7866.5037341884. The cubic root of 61881881 is about 395.5376559142.

The spelling of 61881881 in words is "sixty-one million, eight hundred eighty-one thousand, eight hundred eighty-one".