61431377616 has 240 divisors, whose sum is σ = 217186634880. Its totient is φ = 16519265280.

The previous prime is 61431377593. The next prime is 61431377653. The reversal of 61431377616 is 61677313416.

61431377616 is a `hidden beast` number, since 6 + 14 + 3 + 13 + 7 + 7 + 616 = 666.

61431377616 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 274501 + ... + 445211.

It is an arithmetic number, because the mean of its divisors is an integer number (904944312).

Almost surely, 2^61431377616 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 61431377616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108593317440).

61431377616 is an abundant number, since it is smaller than the sum of its proper divisors (155755257264).

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

61431377616 is a wasteful number, since it uses less digits than its factorization.

61431377616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170759 (or 170740 counting only the distinct ones).

The product of its digits is 381024, while the sum is 45.

The spelling of 61431377616 in words is "sixty-one billion, four hundred thirty-one million, three hundred seventy-seven thousand, six hundred sixteen".