61212729697920 has 2304 divisors, whose sum is σ = 250963122009600. Its totient is φ = 14207598526464.

The previous prime is 61212729697913. The next prime is 61212729697921. The reversal of 61212729697920 is 2979692721216.

61212729697920 is a `hidden beast` number, since 61 + 212 + 7 + 296 + 9 + 79 + 2 + 0 = 666.

It is not an unprimeable number, because it can be changed into a prime (61212729697921) 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 287 ways as a sum of consecutive naturals, for example, 36720292927 + ... + 36720294593.

It is an arithmetic number, because the mean of its divisors is an integer number (108924966150).

Almost surely, 2^{61212729697920} is an apocalyptic number.

61212729697920 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 61212729697920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (125481561004800).

61212729697920 is an abundant number, since it is smaller than the sum of its proper divisors (189750392311680).

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

61212729697920 is a wasteful number, since it uses less digits than its factorization.

61212729697920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1797 (or 1756 counting only the distinct ones).

The product of its (nonzero) digits is 20575296, while the sum is 63.

The spelling of 61212729697920 in words is "sixty-one trillion, two hundred twelve billion, seven hundred twenty-nine million, six hundred ninety-seven thousand, nine hundred twenty".