61208640 has 168 divisors, whose sum is σ = 215039448. Its totient is φ = 15974400.

The previous prime is 61208639. The next prime is 61208657. The reversal of 61208640 is 4680216.

61208640 is a `hidden beast` number, since 6 + 12 + 0 + 8 + 640 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 30206016 + 31002624 = 5496^2 + 5568^2 .

It is a super-3 number, since 3×61208640³ (a number of 24 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 152440 + ... + 152840.

Almost surely, 2^61208640 is an apocalyptic number.

61208640 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 61208640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107519724).

61208640 is an abundant number, since it is smaller than the sum of its proper divisors (153830808).

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

61208640 is a wasteful number, since it uses less digits than its factorization.

61208640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 477 (or 464 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 61208640 is about 7823.5950815466. The cubic root of 61208640 is about 394.0980112957.

Adding to 61208640 its reverse (4680216), we get a palindrome (65888856).

The spelling of 61208640 in words is "sixty-one million, two hundred eight thousand, six hundred forty".