61786271820 has 192 divisors, whose sum is σ = 213395567616. Its totient is φ = 13007416320.

The previous prime is 61786271819. The next prime is 61786271821. The reversal of 61786271820 is 2817268716.

It is an interprime number because it is at equal distance from previous prime (61786271819) and next prime (61786271821).

It is a super-2 number, since 2×61786271820² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 61786271820.

It is not an unprimeable number, because it can be changed into a prime (61786271821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2504787 + ... + 2529333.

It is an arithmetic number, because the mean of its divisors is an integer number (1111435248).

Almost surely, 2^61786271820 is an apocalyptic number.

61786271820 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 61786271820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106697783808).

61786271820 is an abundant number, since it is smaller than the sum of its proper divisors (151609295796).

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

61786271820 is a wasteful number, since it uses less digits than its factorization.

61786271820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25040 (or 25038 counting only the distinct ones).

The product of its (nonzero) digits is 451584, while the sum is 48.

The spelling of 61786271820 in words is "sixty-one billion, seven hundred eighty-six million, two hundred seventy-one thousand, eight hundred twenty".