61551566515516 has 144 divisors (see below), whose sum is σ = 142746393726720. Its totient is φ = 22920652634880.

The previous prime is 61551566515513. The next prime is 61551566515567.

61551566515516 is nontrivially palindromic in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61551566515511) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 63437451 + ... + 64400413.

It is an arithmetic number, because the mean of its divisors is an integer number (991294400880).

Almost surely, 2^{61551566515516} 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 61551566515516, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (71373196863360).

61551566515516 is an abundant number, since it is smaller than the sum of its proper divisors (81194827211204).

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

61551566515516 is a wasteful number, since it uses less digits than its factorization.

61551566515516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 964304 (or 964295 counting only the distinct ones).

The product of its digits is 20250000, while the sum is 58.

The spelling of 61551566515516 in words is "sixty-one trillion, five hundred fifty-one billion, five hundred sixty-six million, five hundred fifteen thousand, five hundred sixteen".