61638804 has 144 divisors (see below), whose sum is σ = 179262720. Its totient is φ = 17740800.

The previous prime is 61638779. The next prime is 61638809. The reversal of 61638804 is 40883616.

It is a happy number.

61638804 is a `hidden beast` number, since 616 + 38 + 8 + 0 + 4 = 666.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61638809) 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 47 ways as a sum of consecutive naturals, for example, 408129 + ... + 408279.

It is an arithmetic number, because the mean of its divisors is an integer number (1244880).

Almost surely, 2^61638804 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61638804, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89631360).

61638804 is an abundant number, since it is smaller than the sum of its proper divisors (117623916).

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

61638804 is a wasteful number, since it uses less digits than its factorization.

61638804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 230 (or 225 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 61638804 is about 7851.0384026573. The cubic root of 61638804 is about 395.0190750816.

The spelling of 61638804 in words is "sixty-one million, six hundred thirty-eight thousand, eight hundred four".