61728380 has 48 divisors (see below), whose sum is σ = 148786176. Its totient is φ = 21072960.

The previous prime is 61728367. The next prime is 61728391. The reversal of 61728380 is 8382716.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 61728380.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37127 + ... + 38753.

It is an arithmetic number, because the mean of its divisors is an integer number (3099712).

Almost surely, 2^61728380 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 61728380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74393088).

61728380 is an abundant number, since it is smaller than the sum of its proper divisors (87057796).

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

61728380 is a wasteful number, since it uses less digits than its factorization.

61728380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1914 (or 1912 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 61728380 is about 7856.7410546613. The cubic root of 61728380 is about 395.2103350218.

The spelling of 61728380 in words is "sixty-one million, seven hundred twenty-eight thousand, three hundred eighty".