61990240256 has 240 divisors, whose sum is σ = 153008064000. Its totient is φ = 24970788864.

The previous prime is 61990240241. The next prime is 61990240259. The reversal of 61990240256 is 65204209916.

It is not an unprimeable number, because it can be changed into a prime (61990240259) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 488112065 + ... + 488112191.

It is an arithmetic number, because the mean of its divisors is an integer number (637533600).

Almost surely, 2^61990240256 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 61990240256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76504032000).

61990240256 is an abundant number, since it is smaller than the sum of its proper divisors (91017823744).

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

61990240256 is an frugal number, since it uses more digits than its factorization.

61990240256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198 (or 155 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 44.

The spelling of 61990240256 in words is "sixty-one billion, nine hundred ninety million, two hundred forty thousand, two hundred fifty-six".