61646562840 has 96 divisors (see below), whose sum is σ = 190073656080. Its totient is φ = 15994741248.

The previous prime is 61646562839. The next prime is 61646562853. The reversal of 61646562840 is 4826564616.

It is a super-3 number, since 3×61646562840³ (a number of 33 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 61646562840.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 23347 + ... + 351906.

Almost surely, 2^61646562840 is an apocalyptic number.

61646562840 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 61646562840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95036828040).

61646562840 is an abundant number, since it is smaller than the sum of its proper divisors (128427093240).

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

61646562840 is a wasteful number, since it uses less digits than its factorization.

61646562840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 375341 (or 375300 counting only the distinct ones).

The product of its (nonzero) digits is 1658880, while the sum is 48.

The spelling of 61646562840 in words is "sixty-one billion, six hundred forty-six million, five hundred sixty-two thousand, eight hundred forty".