61555481 has 4 divisors (see below), whose sum is σ = 66290532. Its totient is φ = 56820432.

The previous prime is 61555471. The next prime is 61555493. The reversal of 61555481 is 18455516.

It is a happy number.

61555481 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 23609881 + 37945600 = 4859^2 + 6160^2 .

It is a cyclic number.

It is not a de Polignac number, because 61555481 - 2¹⁴ = 61539097 is a prime.

It is a super-2 number, since 2×61555481² = 7578154482282722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (61555411) 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, 2367506 + ... + 2367531.

It is an arithmetic number, because the mean of its divisors is an integer number (16572633).

Almost surely, 2^61555481 is an apocalyptic number.

It is an amenable number.

61555481 is a deficient number, since it is larger than the sum of its proper divisors (4735051).

61555481 is a wasteful number, since it uses less digits than its factorization.

61555481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4735050.

The product of its digits is 24000, while the sum is 35.

The square root of 61555481 is about 7845.7301126154. The cubic root of 61555481 is about 394.8409999381.

Adding to 61555481 its sum of digits (35), we get a palindrome (61555516).

The spelling of 61555481 in words is "sixty-one million, five hundred fifty-five thousand, four hundred eighty-one".