61220040 has 128 divisors (see below), whose sum is σ = 216760320. Its totient is φ = 13536000.

The previous prime is 61220021. The next prime is 61220041. The reversal of 61220040 is 4002216.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is not an unprimeable number, because it can be changed into a prime (61220041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 24865 + ... + 27215.

It is an arithmetic number, because the mean of its divisors is an integer number (1693440).

Almost surely, 2^61220040 is an apocalyptic number.

61220040 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61220040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108380160).

61220040 is an abundant number, since it is smaller than the sum of its proper divisors (155540280).

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

61220040 is a wasteful number, since it uses less digits than its factorization.

61220040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2403 (or 2399 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 61220040 is about 7824.3236129393. The cubic root of 61220040 is about 394.1224764608.

Adding to 61220040 its reverse (4002216), we get a palindrome (65222256).

The spelling of 61220040 in words is "sixty-one million, two hundred twenty thousand, forty".