61977871872 has 400 divisors, whose sum is σ = 215778525600. Its totient is φ = 17703899136.

The previous prime is 61977871871. The next prime is 61977871897. The reversal of 61977871872 is 27817877916.

61977871872 is a `hidden beast` number, since 619 + 7 + 7 + 8 + 7 + 1 + 8 + 7 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61977871871) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 14222718 + ... + 14227074.

It is an arithmetic number, because the mean of its divisors is an integer number (539446314).

Almost surely, 2^61977871872 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 61977871872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107889262800).

61977871872 is an abundant number, since it is smaller than the sum of its proper divisors (153800653728).

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

61977871872 is an frugal number, since it uses more digits than its factorization.

61977871872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4408 (or 4369 counting only the distinct ones).

The product of its digits is 16595712, while the sum is 63.

The spelling of 61977871872 in words is "sixty-one billion, nine hundred seventy-seven million, eight hundred seventy-one thousand, eight hundred seventy-two".