61540420 has 24 divisors (see below), whose sum is σ = 131675544. Its totient is φ = 24151296.

The previous prime is 61540417. The next prime is 61540421. The reversal of 61540420 is 2404516.

It can be written as a sum of positive squares in 4 ways, for example, as 10188864 + 51351556 = 3192^2 + 7166^2 .

It is a junction number, because it is equal to n+sod(n) for n = 61540391 and 61540400.

It is not an unprimeable number, because it can be changed into a prime (61540421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27969 + ... + 30088.

It is an arithmetic number, because the mean of its divisors is an integer number (5486481).

Almost surely, 2^61540420 is an apocalyptic number.

It is an amenable number.

61540420 is an abundant number, since it is smaller than the sum of its proper divisors (70135124).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61540420 is a wasteful number, since it uses less digits than its factorization.

61540420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58119 (or 58117 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 61540420 is about 7844.7702324542. The cubic root of 61540420 is about 394.8087949242.

Adding to 61540420 its reverse (2404516), we get a palindrome (63944936).

The spelling of 61540420 in words is "sixty-one million, five hundred forty thousand, four hundred twenty".