61005640 has 32 divisors (see below), whose sum is σ = 137554560. Its totient is φ = 24350400.

The previous prime is 61005631. The next prime is 61005641. The reversal of 61005640 is 4650016.

It is a super-2 number, since 2×61005640² = 7443376223619200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (61005641) 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, 21505 + ... + 24175.

It is an arithmetic number, because the mean of its divisors is an integer number (4298580).

Almost surely, 2^61005640 is an apocalyptic number.

It is an amenable number.

61005640 is an abundant number, since it is smaller than the sum of its proper divisors (76548920).

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

61005640 is a wasteful number, since it uses less digits than its factorization.

61005640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3253 (or 3249 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 61005640 is about 7810.6107315625. The cubic root of 61005640 is about 393.6618500916.

Adding to 61005640 its reverse (4650016), we get a palindrome (65655656).

The spelling of 61005640 in words is "sixty-one million, five thousand, six hundred forty".