61545640 has 64 divisors (see below), whose sum is σ = 151320960. Its totient is φ = 22391040.

The previous prime is 61545623. The next prime is 61545647. The reversal of 61545640 is 4654516.

61545640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (61545647) 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 15 ways as a sum of consecutive naturals, for example, 36087 + ... + 37753.

It is an arithmetic number, because the mean of its divisors is an integer number (2364390).

Almost surely, 2^61545640 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 61545640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (75660480).

61545640 is an abundant number, since it is smaller than the sum of its proper divisors (89775320).

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

61545640 is a wasteful number, since it uses less digits than its factorization.

61545640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1762 (or 1758 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 31.

The square root of 61545640 is about 7845.1029311284. The cubic root of 61545640 is about 394.8199574720.

The spelling of 61545640 in words is "sixty-one million, five hundred forty-five thousand, six hundred forty".