61929401856 has 640 divisors, whose sum is σ = 204586905600. Its totient is φ = 16618291200.

The previous prime is 61929401851. The next prime is 61929401867. The reversal of 61929401856 is 65810492916.

It is a junction number, because it is equal to n+sod(n) for n = 61929401799 and 61929401808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61929401851) by changing a digit.

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 63 ways as a sum of consecutive naturals, for example, 1015236066 + ... + 1015236126.

It is an arithmetic number, because the mean of its divisors is an integer number (319667040).

Almost surely, 2^61929401856 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 61929401856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102293452800).

61929401856 is an abundant number, since it is smaller than the sum of its proper divisors (142657503744).

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

61929401856 is an equidigital number, since it uses as much as digits as its factorization.

61929401856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191 (or 161 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 51.

The spelling of 61929401856 in words is "sixty-one billion, nine hundred twenty-nine million, four hundred one thousand, eight hundred fifty-six".