61816239936 has 840 divisors, whose sum is σ = 221013357312. Its totient is φ = 17061580800.

The previous prime is 61816239913. The next prime is 61816239937. The reversal of 61816239936 is 63993261816.

61816239936 is a `hidden beast` number, since 6 + 1 + 8 + 1 + 623 + 9 + 9 + 3 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

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

Its product of digits (2519424) is a multiple of the sum of its prime divisors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61816239937) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 1994072241 + ... + 1994072271.

Almost surely, 2^61816239936 is an apocalyptic number.

61816239936 is a gapful number since it is divisible by the number (66) 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 61816239936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110506678656).

61816239936 is an abundant number, since it is smaller than the sum of its proper divisors (159197117376).

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

61816239936 is a wasteful number, since it uses less digits than its factorization.

61816239936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122 (or 64 counting only the distinct ones).

The product of its digits is 2519424, while the sum is 54.

The spelling of 61816239936 in words is "sixty-one billion, eight hundred sixteen million, two hundred thirty-nine thousand, nine hundred thirty-six".