61781465262216 has 256 divisors, whose sum is σ = 181709805404160. Its totient is φ = 17137895604480.

The previous prime is 61781465262211. The next prime is 61781465262287. The reversal of 61781465262216 is 61226256418716.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (61781465262211) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1034714235 + ... + 1034773941.

It is an arithmetic number, because the mean of its divisors is an integer number (709803927360).

Almost surely, 2^{61781465262216} 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 61781465262216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90854902702080).

61781465262216 is an abundant number, since it is smaller than the sum of its proper divisors (119928340141944).

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

61781465262216 is a wasteful number, since it uses less digits than its factorization.

61781465262216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60624 (or 60620 counting only the distinct ones).

The product of its digits is 11612160, while the sum is 57.

The spelling of 61781465262216 in words is "sixty-one trillion, seven hundred eighty-one billion, four hundred sixty-five million, two hundred sixty-two thousand, two hundred sixteen".