61040 has 40 divisors (see below), whose sum is σ = 163680. Its totient is φ = 20736.

The previous prime is 61031. The next prime is 61043. The reversal of 61040 is 4016.

It is a tau number, because it is divible by the number of its divisors (40).

It is a nialpdrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61043) by changing a digit.

61040 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 506 + ... + 614.

It is an arithmetic number, because the mean of its divisors is an integer number (4092).

2⁶¹⁰⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81840).

61040 is an abundant number, since it is smaller than the sum of its proper divisors (102640).

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

61040 is a wasteful number, since it uses less digits than its factorization.

61040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129 (or 123 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 61040 is about 247.0627450669. The cubic root of 61040 is about 39.3735743164.

Subtracting from 61040 its product of nonzero digits (24), we obtain a palindrome (61016).

Adding to 61040 its reverse (4016), we get a palindrome (65056).

The spelling of 61040 in words is "sixty-one thousand, forty".