61391425536 has 312 divisors, whose sum is σ = 205503671360. Its totient is φ = 17294819328.

The previous prime is 61391425531. The next prime is 61391425547. The reversal of 61391425536 is 63552419316.

61391425536 is a `hidden beast` number, since 6 + 1 + 3 + 91 + 4 + 2 + 553 + 6 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 61391425491 and 61391425500.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61391425531) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18835875 + ... + 18839133.

Almost surely, 2^61391425536 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 61391425536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102751835680).

61391425536 is an abundant number, since it is smaller than the sum of its proper divisors (144112245824).

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

61391425536 is a wasteful number, since it uses less digits than its factorization.

61391425536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3369 (or 3344 counting only the distinct ones).

The product of its digits is 583200, while the sum is 45.

The spelling of 61391425536 in words is "sixty-one billion, three hundred ninety-one million, four hundred twenty-five thousand, five hundred thirty-six".