61259120640 has 380 divisors, whose sum is σ = 220005505236. Its totient is φ = 16307453952.

The previous prime is 61259120639. The next prime is 61259120651. The reversal of 61259120640 is 4602195216.

61259120640 is a `hidden beast` number, since 6 + 1 + 2 + 5 + 9 + 1 + 2 + 0 + 640 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 46905163776 + 14353956864 = 216576^2 + 119808^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 61259120595 and 61259120604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 106168032 + ... + 106168608.

Almost surely, 2^61259120640 is an apocalyptic number.

61259120640 is a gapful number since it is divisible by the number (60) 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 61259120640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110002752618).

61259120640 is an abundant number, since it is smaller than the sum of its proper divisors (158746384596).

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

61259120640 is an frugal number, since it uses more digits than its factorization.

61259120640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 630 (or 587 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The spelling of 61259120640 in words is "sixty-one billion, two hundred fifty-nine million, one hundred twenty thousand, six hundred forty".