61215644 has 24 divisors (see below), whose sum is σ = 128876160. Its totient is φ = 24854256.

The previous prime is 61215643. The next prime is 61215653. The reversal of 61215644 is 44651216.

61215644 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61215643) 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 7 ways as a sum of consecutive naturals, for example, 57002 + ... + 58065.

It is an arithmetic number, because the mean of its divisors is an integer number (5369840).

Almost surely, 2^61215644 is an apocalyptic number.

It is an amenable number.

61215644 is an abundant number, since it is smaller than the sum of its proper divisors (67660516).

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

61215644 is a wasteful number, since it uses less digits than its factorization.

61215644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115097 (or 115095 counting only the distinct ones).

The product of its digits is 5760, while the sum is 29.

The square root of 61215644 is about 7824.0426890451. The cubic root of 61215644 is about 394.1130427096.

The spelling of 61215644 in words is "sixty-one million, two hundred fifteen thousand, six hundred forty-four".