61305140 has 24 divisors (see below), whose sum is σ = 138644520. Its totient is φ = 22635648.

The previous prime is 61305131. The next prime is 61305149. The reversal of 61305140 is 4150316.

It is an interprime number because it is at equal distance from previous prime (61305131) and next prime (61305149).

It can be written as a sum of positive squares in 4 ways, for example, as 10010896 + 51294244 = 3164^2 + 7162^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61305149) 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, 117635 + ... + 118154.

It is an arithmetic number, because the mean of its divisors is an integer number (5776855).

Almost surely, 2^61305140 is an apocalyptic number.

It is an amenable number.

61305140 is an abundant number, since it is smaller than the sum of its proper divisors (77339380).

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

61305140 is a wasteful number, since it uses less digits than its factorization.

61305140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235811 (or 235809 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 61305140 is about 7829.7598941475. The cubic root of 61305140 is about 394.3050108828.

Adding to 61305140 its reverse (4150316), we get a palindrome (65455456).

The spelling of 61305140 in words is "sixty-one million, three hundred five thousand, one hundred forty".