61520517131640 has 512 divisors, whose sum is σ = 233233344000000. Its totient is φ = 12649025765376.

The previous prime is 61520517131639. The next prime is 61520517131687. The reversal of 61520517131640 is 4613171502516.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 61520517131592 and 61520517131601.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 410146576 + ... + 410296544.

It is an arithmetic number, because the mean of its divisors is an integer number (455533875000).

Almost surely, 2^{61520517131640} is an apocalyptic number.

61520517131640 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 61520517131640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116616672000000).

61520517131640 is an abundant number, since it is smaller than the sum of its proper divisors (171712826868360).

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

61520517131640 is a wasteful number, since it uses less digits than its factorization.

61520517131640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151279 (or 151275 counting only the distinct ones).

The product of its (nonzero) digits is 151200, while the sum is 42.

The spelling of 61520517131640 in words is "sixty-one trillion, five hundred twenty billion, five hundred seventeen million, one hundred thirty-one thousand, six hundred forty".