61136640 has 288 divisors, whose sum is σ = 228110400. Its totient is φ = 15482880.

The previous prime is 61136633. The next prime is 61136651. The reversal of 61136640 is 4663116.

61136640 is a `hidden beast` number, since 6 + 1 + 13 + 6 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1002210 + ... + 1002270.

It is an arithmetic number, because the mean of its divisors is an integer number (792050).

Almost surely, 2^61136640 is an apocalyptic number.

61136640 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 61136640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114055200).

61136640 is an abundant number, since it is smaller than the sum of its proper divisors (166973760).

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

61136640 is a wasteful number, since it uses less digits than its factorization.

61136640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120 (or 100 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 61136640 is about 7818.9922624338. The cubic root of 61136640 is about 393.9434242418.

Adding to 61136640 its reverse (4663116), we get a palindrome (65799756).

It can be divided in two parts, 61136 and 640, that added together give a triangular number (61776 = T₃₅₁).

The spelling of 61136640 in words is "sixty-one million, one hundred thirty-six thousand, six hundred forty".