61399804536 has 288 divisors, whose sum is σ = 207954695520. Its totient is φ = 15976120320.

The previous prime is 61399804517. The next prime is 61399804541. The reversal of 61399804536 is 63540899316.

61399804536 is a `hidden beast` number, since 6 + 13 + 9 + 98 + 0 + 4 + 536 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 8230120 + ... + 8237576.

It is an arithmetic number, because the mean of its divisors is an integer number (722064915).

Almost surely, 2^61399804536 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 61399804536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103977347760).

61399804536 is an abundant number, since it is smaller than the sum of its proper divisors (146554890984).

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

61399804536 is a wasteful number, since it uses less digits than its factorization.

61399804536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7555 (or 7517 counting only the distinct ones).

The product of its (nonzero) digits is 4199040, while the sum is 54.

The spelling of 61399804536 in words is "sixty-one billion, three hundred ninety-nine million, eight hundred four thousand, five hundred thirty-six".